Patent Publication Number: US-2007106594-A1

Title: Electronic ownership control system and method

Description:
This application claims the benefit of U.S. provisional patent application Ser. No. 60/184,867, filed Feb. 25, 2000. 
    
    
     BACKGROUND OF THE INVENTION  
      This invention relates to electronic trading systems. More particularly, this invention relates to fractional ownership control systems and methods that provide for the electronic control of fractional ownership interests in personal property, real property and other legal interests.  
      Fractional property ownership is common in our society. People and corporations may co-own almost any type of personal or real property in a variety of arrangements. Each co-owner may, for example, have an undivided interest in personal or real property with the right to use the entire property at any time. This is sometimes referred to as a “tenancy in common.” Condominiums and co-operative ownership (sometimes referred to as “co-ops”) are additional examples of types of real property fractional ownership arrangements.  
      In some arrangements, co-owners may have the right to use property only during specified periods of time. Co-owners of a computer system, for example, may own a time period during which their jobs are processed. Co-owners of real property, for example, may each have an undivided interest in an entire property, but only have the right to use the property during a specified period of time. In some time-based arrangements, co-owners may own real property only during particular time periods, such as a week, during which the owners actually own and may use the property. These are sometimes referred to as “deeded weeks,” and are used typically in time-share vacation ownership arrangements. In other vacation ownership arrangements, co-owners have points that they can use to obtain particular weeks of use at particular properties. Co-owners in this type of arrangement may have only a right to use the property, and not a direct ownership interest in the property. In still other vacation ownership arrangements, people own weeks of use in a network of properties, rather than any direct ownership interest in a particular property.  
      Fractional ownership can decrease the value and liquidity of real and personal property. Would-be purchasers must deal with each owner in order to obtain the entire interest in the property. This may increase transaction costs for the purchase, especially when co-owners are geographically diverse parties. In arrangements where people own weeks of use in a network of properties, rather than any direct ownership interest in a particular property, the value of the sum of the parts may be significantly less than the value of the whole. A purchaser of each co-owners&#39; interest would only obtain each co-owner&#39;s right to use the property. If property were purchased from the real owner (i.e., the network), the purchaser would have to take the property subject to all of the co-owners&#39; (i.e., users&#39;) rights.  
      One approach for increasing the liquidity of co-owned real property has been to provide each co-owner with drag-along rights. Drag-along rights include the right of a co-owner to require other co-owners to sell their interests in a commodity at fair market value when the co-owner wishes to sell his or her own fractional interest in the commodity. Drag-along rights may increase the liquidity of a commodity because they may ensure that a single co-owner can compel the sale of, and a purchaser can purchase, the entire interest in a commodity.  
      Even the use of drag-along rights, when coupled with a small number of co-owners, may not provide for the optimal value and liquidity of real property if the rights cannot be managed and transferred in an efficient manner. Each owner may, for example, need to execute necessary transfer documents (e.g., contracts of sale, deeds, etc.), and each owner may need to be compensated for his or her interest in the property. The difficulty in transferring property subject to drag-along rights may be exacerbated if co-owners are geographically disparate.  
      It would be desirable, therefore, to provide an electronic ownership control system that separates the ownership of commodities from the management of the commodities by putting owners into direct ownership of commodities that have traditionally been right-to-use types of commodities, or that have traditionally been owned by a single party who sells the output of a commodity.  
      It would also be desirable to provide an electronic ownership control system that allows geographically disparate potential co-owners to coordinate their interests and jointly acquire commodities.  
      It would also be desirable to provide an electronic ownership control system that provides for the electronic transfer of ownership in fractionally-owned commodities.  
      It would also be desirable to provide an electronic ownership control system that provides for the transfer of ownership in fractionally-owned commodities that are co-owned subject to drag-along rights.  
      It would also be desirable to provide an electronic ownership control system that provides for notifying co-owners of a potential sale of another co-owner&#39;s interest in a co-owned commodity.  
      It would also be desirable to provide an electronic ownership control system that provides for notifying co-owners of a potential sale of a co-owned commodity in which the other co-owners have drag-along rights.  
      It would also be desirable to provide an electronic transfer ownership system that provides for allowing co-owners of a commodity to purchase the interest of a selling co-owner when the selling co-owner attempts to sell his interest in the property.  
      It would also be desirable to provide an electronic ownership control system that provides for notifying co-owners of an opportunity to sell their interests in a co-owned property when a co-owner attempts to sell his or her interest in the property (sometimes referred to herein as “tag-along” rights).  
      It would also be desirable to provide an electronic ownership control system that provides non-user co-owners with opportunities to exercise drag-along or tag-along rights.  
     SUMMARY OF THE INVENTION  
      It is an object of some embodiments of the present invention to provide an electronic ownership control system that separates the ownership of underlying commodities from the management of the commodities by putting owners into direct ownership of underlying commodities that have traditionally been right-to-use types of commodities, or that have traditionally been owned by a single party who sells the output of a commodity.  
      It is an object of some embodiments of the present invention to provide an electronic ownership control system that allows geographically disparate potential owners to coordinate their interests and jointly acquire commodities.  
      It is an object of some embodiments of the present invention to provide an electronic ownership control system that provides for the electronic transfer of ownership in fractionally-owned commodities.  
      It is an object of some embodiments of the present invention to provide an electronic ownership control system that provides for the transfer of ownership in fractionally-owned commodities that are co-owned subject to drag-along rights.  
      It is an object of some embodiments of the present invention to provide an electronic ownership control system that provides for notifying co-owners of a potential sale of another co-owner&#39;s interest in a co-owned commodity.  
      It is an object of some embodiments of the present invention to provide an electronic ownership control system that provides for notifying co-owners of a potential sale of a co-owned commodity in which the other co-owners have drag-along rights.  
      It is an object of some embodiments of the present invention to provide an electronic transfer ownership system that provides for allowing co-owners of a commodity to purchase the interest of a selling co-owner when the selling co-owner attempts to sell his interest in the property.  
      It is an object of some embodiments of the present invention to provide an electronic ownership control system that provides for notifying co-owners of an opportunity to sell their interest in a co-owned property as provided for by tag-along rights.  
      It is an object of some embodiments of the present invention to provide an electronic ownership control system that provides non-user co-owners with opportunities to exercise drag-along, tag-along, first refusal, first offer, or veto rights.  
      Various features and embodiments of the present invention are described in Vlahoplus et al. U.S. provisional patent application Ser. No. 60/184,867, filed Feb. 25, 2000, which is hereby incorporated by reference herein in its entirety.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The above and other objects and advantages of the invention will be apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which:  
       FIGS. 1   a  and  1   b  show illustrative on-line and client/server arrangements for an electronic fractional ownership control system, in accordance with the present invention;  
       FIG. 2  shows an illustrative arrangement for the Internet enabled access devices of  FIG. 1   a,  in accordance with the present invention;  
       FIG. 3  shows a generalized flowchart of steps involved in operating the electronic fractional ownership control system, in accordance with the present invention;  
       FIG. 4  shows a flowchart of illustrative steps involved in providing users with opportunities to enter commodity information, in accordance with the present invention;  
       FIGS. 5, 6 , and  7  are flowcharts of illustrative steps involved in providing users with opportunities to purchase, sell, and trade commodities, in accordance with the present invention;  
       FIG. 8  is a flowchart of illustrative steps involved in initiating the transfer of ownership of commodities, in accordance with the present invention;  
       FIG. 9  is a flowchart of illustrative steps involved in providing users with opportunities to participate in or initiate auctions for identified commodities or classes of commodities, in accordance with the present invention;  
       FIG. 10  is a flowchart of illustrative steps involved in addressing co-ownership rights in the contexts of purchases, sales and trades, in accordance with the present invention;  
       FIG. 11  is a flowchart of illustrative steps involved in generating and providing transfer and other documents, in accordance with the present invention;  
       FIG. 12  is a flowchart of illustrative steps involved in providing users with notification of changes in co-ownership information, in accordance with the present invention;  
       FIG. 13  is a flowchart of illustrative steps involved in providing users with opportunities to transfer commodities among networks, in accordance with the present invention;  
       FIG. 14  shows an illustrative login page, in accordance with the present invention;  
       FIG. 15  shows an illustrative user information page that the system may provide to a new user, in accordance with the present invention;  
       FIG. 16   a  shows an illustrative portfolio page, in accordance with the present invention;  
       FIG. 16   b  shows an illustrative information page that the system may provide in response to a user indicating a desire to view or edit user information, in accordance with the present invention;  
       FIG. 17  shows an illustrative associated parties page that the system may provide in response to a user indicating a desire to enter associated party information, in accordance with the present invention;  
       FIG. 18  shows an illustrative attorneys page that the system may provide in response to a user indicating a desire to view, enter, or edit attorney information, in accordance with the present invention;  
       FIG. 19  shows an illustrative attorney information page, in accordance with the present invention;  
       FIG. 20  shows an illustrative real estate brokers page that the system may provide in response to a user indicating a desire to view, enter, or edit real estate broker information, in accordance with the present invention;  
       FIG. 21  shows an illustrative real estate broker information page, in accordance with the present invention;  
       FIG. 22   a  shows an illustrative mortgage brokers page that the system may provide in response to a user indicating a desire to view, enter, or edit mortgage broker information, in accordance with the present invention;  
       FIG. 22   b  shows an illustrative mortgage broker information page, in accordance with the present invention;  
       FIG. 23   a  shows an illustrative friends page that the system may provide in response to a user indicating a desire to view, enter, or edit friends information, in accordance with the present invention;  
       FIG. 23   b  shows an illustrative friend information page, in accordance with the present invention;  
       FIG. 24   a  shows an illustrative commodities type selection page, in accordance with the present invention;  
       FIG. 24   b  shows an illustrative commodities information page for a commodity of the type indicated in  FIG. 24   a,  in accordance with the present invention;  
       FIG. 24   c  shows an illustrative specialized hourly consumption page for providing a user with an opportunity to define utility requirements within given time periods, in accordance with the principles of the present invention;  
       FIG. 25   a  shows an illustrative commodities type selection page, in accordance with the present invention;  
       FIG. 25   b  shows an illustrative ownership selection page, in accordance with the present invention;  
       FIG. 25   c  shows an illustrative commodities information page for a commodity of the type indicated in  FIG. 25   a,  in accordance with the present invention;  
       FIG. 26  shows an illustrative co-owners page that the system may provide in response to a user indicating a desire to generate or access a list of co-owners for a commodity, in accordance with the present invention;  
       FIGS. 27   a - 27   c  show illustrative additional documents pages for providing a user with an opportunity to provide documents for a commodity, in accordance with the present invention;  
       FIG. 28   a  shows an illustrative commodities information page for commodities of the type stock, in accordance with the present invention;  
       FIG. 28   b  shows an illustrative additional news page that the system may provide in response to a user indicating a desire to view additional news for a commodity, in accordance with the present invention;  
       FIG. 28   c  shows an illustrative price history page that the system may provide in response to a user indicating a desire to view the recent price history for a commodity, in accordance with the present invention;  
       FIG. 28   d  shows an illustrative request received page that the system may provide in response to a user indicating a desire to view received requests for a commodity, in accordance with the present invention;  
       FIG. 29   a  shows an illustrative commodities information page for right-to-use vacation property, in accordance with the present invention;  
       FIG. 29   b  shows an illustrative co-owners page that the system may provide in response to a user indicating a desire to view co-owners for a commodity, in accordance with the present invention;  
       FIGS. 29   c  and  29   d  show pages that the system may provide in response to a user indicating a desire to trade a commodity, in accordance with the present invention;  
       FIG. 29   e  shows an illustrative request received page that the system may provide in response to a user indicating a desire to view received requests for a commodity, in accordance with the present invention;  
       FIG. 30   a  shows an illustrative commodities information page for co-owned residential real property with drag-along rights, in accordance with the present invention;  
       FIG. 30   b  shows an illustrative co-owners page that the system may provide in response to a user indicating a desire to view co-owners for a commodity, in accordance with the present invention;  
       FIG. 30   c  shows an illustrative co-owner information page that the system may provide in response to a user indicating a desire to view information about a co-owner, in accordance with the present invention;  
       FIG. 30   d  shows a page that the system may provide in response to a user indicating a desire to view additional documents for a commodity, in accordance with the present invention;  
       FIG. 30   e  shows an illustrative request received page that the system may provide in response to a user indicating a desire to view received requests for a commodity, in accordance with the present invention;  
       FIG. 31   a  shows an illustrative commodities information page for commodities of the type utilities/electrical, in accordance with the present invention;  
       FIGS. 31   b  and  31   c  show illustrative pages that the system may provide in response to a user indicating a desire to split a commodity, in accordance with the present invention;  
       FIG. 32  shows an illustrative commodities information page for deeded-week vacation property with drag-along and tag-along rights, in accordance with the present invention;  
       FIGS. 33   a - 33   e  show illustrative pages that the system may provide in response to a user indicating a desire to purchase a commodity, such as crude oil, in accordance with the present invention;  
       FIGS. 34   a - 34   d  show illustrative pages that the system may provide in response to a user indicating a desire to purchase a commodity, such as vacation property, in accordance with the present invention;  
       FIGS. 35   a - 35   d  show illustrative pages that the system may provide in response to a user indicating a desire to view and meet or counter asks for commodities, in accordance with the present invention;  
       FIGS. 36   a - 36   c  show illustrative pages that the system may provide in response to a user indicating a desire to participate in auctions for commodities, in accordance with the present invention;  
       FIG. 36   d  shows an illustrative page that the system may provide in response to a user indicating a desire to provide friends an opportunity to join in a purchase, in accordance with the present invention;  
       FIGS. 37   a - 37   c  show illustrative pages that provide a user with an opportunity to browse properties and define bids in accordance with the present invention;  
       FIGS. 38   a  and  38   b  show illustrative pages for providing users with opportunities to define bids and view matched properties, in accordance with the present invention;  
       FIG. 39  shows an illustrative select commodity page that the system may provide in response to a user indicating a desire to sell commodities, in accordance with the present invention;  
       FIGS. 40   a  and  40   b  show illustrative pages that the system may provide to a user with an opportunity to sell and auction stocks in accordance with the present invention;  
       FIGS. 41   a  and  41   b  show illustrative pages that the system may provide to provide a user with an opportunity to sell and auction right-to-use type vacation property in accordance with the present invention;  
       FIGS. 42   a  and  42   b  show illustrative pages that the system may provide to a user with an opportunity to sell co-owned residential property with drag-along rights, in accordance with the present invention;  
       FIGS. 43   a  and  43   b  show illustrative pages that the system may provide to a user with an opportunity to sell and auction commodities of type utilities/electrical, in accordance with the present invention;  
       FIGS. 44   a  and  44   b  show illustrative pages that the system may provide to a user with an opportunity to sell and auction deeded-week vacation property, in accordance with the present invention;  
       FIGS. 45   a - 45   c  show illustrative pages that the system may provide to a user with an opportunity to define sales requests using expressions, in accordance with the present invention;  
       FIG. 46  shows an illustrative commodity selection page that the system may provide in response to a user indicating a desire to trade a commodity, in accordance with the present invention;  
       FIGS. 47   a - 47   k  show illustrative pages that the system may provide to provide users with opportunities to trade illustrative types of commodities, in accordance with the present invention;  
       FIGS. 48   a - 48   f  show illustrative pages that the system may provide to provide users with opportunities to perform illustrative maintenance functions, in accordance with the present invention; and  
       FIG. 49  shows an illustrative message page with illustrative messages, in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS  
      In accordance with this invention, there is provided an electronic fractional ownership control system. The fractional ownership control system of the present invention provides users with opportunities to purchase, sell, trade or manage commodities that are fractionally owned by a number of co-owners. In this way, the system may allow users to fractionally own commodities while the system provides for the maintenance, purchase, sale, and trade of fractionally-owned commodities. As used herein, “commodity” and “commodities” are intended to include any personal property, whether tangible or intangible, real property, or a combination thereof, in which users of the system may have an ownership interest. These terms are also intended to include any legal interest or right that may transferred. Commodities may be, for example, aircraft, spacecraft, real property (residential, vacation, industrial and commercial), bonds, bills, notes, stocks, derivatives, marine rights, utility output (e.g., electricity, gas, water, etc.), distribution capacities (e.g., ground, air, and water shipping, pipelines, electrical grids, airport landing slots, etc.), computer hardware or processing capacity (e.g., servers, mainframes, etc.), computer software, natural resources and related items (e.g., oil, gas, timber, oil wells, radio frequency spectrum rights, etc.), produced resources (e.g., grain, coffee, grapes, etc.), intellectual property (e.g., patents, copyrights, trademarks, etc.), or any other type of real or personal property. Commodities may also include legal rights or interests, such as rights to use, make or sell products or services. For example, a commodity may be a software license. A “lot” or “block” of aggregated units may also be referred to herein as a commodity. The units may each be individually owned or, alternatively, each owner may have an undivided interest in the lot or block. For example, one or more users may each own a unit of stock. The owners&#39; units may be aggregated into a lot or block of stocks. The lot of stocks in this example is a commodity, with each owner having an ownership interest in his or her own unit of stock and therefore a fractional ownership interest in the block. As another example, a block commodity may be a group software license that is owned by a number of co-owners. Each owner may have the right to use a copy of the software under one license.  
      As used herein, fractional ownership interests may be fractional interests in a singular commodity, an interest in one or more units that are aggregated by the system into a lot or block commodity, or an undivided interest in a lot or block of units. Fractional ownership interests may include, for example, undivided or divided interests in personal property, condominium ownership, cooperative ownership, deeded time periods (e.g., deeded-weeks of ownership in real property such as some time shares), or any other suitable interest. Purchasers of commodities may purchase the entire interest in a commodity, or a fractional interest in a commodity.  
      Fractional ownership interests may include the right to exclusively use a commodity for a period of time. In some fractional ownership arrangements, the exclusive right to use a commodity (e.g., real property, distribution capacity, computer processing capacity, etc.), may be temporally constrained. Co-owners may, for example, have the right to use a commodity only during a fixed time period (hereinafter sometimes referred to as a “fixed period arrangement”). In another arrangement, co-owners may have the right to use a commodity for a fixed amount of time (e.g., one week), but the time period during which the fixed amount of time occurs may change (hereinafter sometimes referred to as a “floating right arrangement”). In still another exclusive use arrangement, co-owners may have a total amount of points that they may exchange for the use of one or more commodities during one or more time periods (hereinafter sometimes referred to as a “point system arrangement”). Users may also share commodities concurrently (i.e., common use). Any other suitable concurrent or exclusive use arrangement may be used.  
      The system may provide users with opportunities to purchase, sell, trade and manage commodities and fractional interests in commodities. The system may determine, or users may indicate, the type of commodity the users wish to purchase, sell, trade or manage. The system may provide display screens or web pages with interface elements, information, and features that are specialized to the type of commodity. The specialization of display screens or web pages based on commodity type may allow a system provider to provide a single system that provides geographically disparate owners of different types of commodities with opportunities to purchase, sell, trade and manage their commodities. This may broaden the user base of the system as compared to a system that merely trades a single type of commodity, and may provide the system provider with increased income opportunities. The system provider may, for example, receive increased income from users should the provider decide to charge a per-user or per-transaction fee. The increased user base may also make the system more attractive to advertisers, resulting in increased advertisement revenue.  
      The system may also provide for the increased liquidity of fractionally-owned commodities by providing for the purchase, trade, or sale of fractionally-owned commodities among users who own the commodities subject to drag-along or tag-along rights of other co-owners. As used herein, drag-along rights include the right of a co-owner to require other co-owners to sell their interests in a commodity at fair market value when the original co-owner wishes to sell his or her own fractional interest in the commodity. As used herein, tag-along rights include the right of a co-owner to require another co-owner to sell the original co-owner&#39;s interest along with the other co-owner&#39;s interest, when the other co-owner  9  sells his or her interest. Co-owners who are dragged-along or who tag-along may be compensated for their interest at the fair market value or at such other price terms as defined in the co-ownership agreement. Drag-along and tag-along rights may be continuous, periodic, continuous after a period or otherwise. For example, each co-owner might have the right at any time to cause a sale of all interests in a commodity (i.e., continuous rights). Alternatively, the owner might have the right to force a sale only once every five years (i.e., periodic rights), or any time after five years have passed (i.e., rights that are continuous after a period).  
      Drag-along and tag-along rights may increase the liquidity of a commodity because they may ensure that a single co-owner can sell, and a purchaser can purchase, the entire interest in a commodity. The ability to sell or purchase an entire commodity may be desirable when, for example, the entire ownership interest in a commodity is more valuable than the sum of the values of the individual ownership interests. Drag-along and tag-along rights may also ensure a purchaser that an entire commodity can be purchased without the danger of one or more co-owners refusing to sell. This may make fractional ownership more attractive to owners than it would be in the absence of such rights. In some embodiments, co-owners may have veto, first refusal, or first offer rights.  
      The system may provide users with opportunities to purchase, sell, or trade specific unique or fungible commodities (e.g., a specific property, stock, natural resource from a particular provider, a particular unit in a condominium, a particular time share property for a particular week, etc.). The system may also provide users with opportunities to purchase, sell, or trade classes of commodities (e.g., ten thousand barrels of oil from any provider, one hundred tons of shipping capacity from any distributor, any two-bedroom condominium in a particular price range within a specific radius of a particular attraction, any deeded-week of ownership in a facility for a particular week, etc.). The system may also provide users with opportunities to rent fractional interests in commodities (e.g., deeded weeks, processing capacity, etc.). The system may, for example, provide users with opportunities to access information on commodities. The system may provide users with opportunities to immediately purchase available commodities at a posted sale price, or may provide users with opportunities to make offers for available commodities when a posted sale price is undesirable. The system may also provide users with opportunities to make offers for commodities that are not yet for sale.  
      The system may provide users with opportunities to set the price at which they buy or sell commodities. The system may provide buyers and sellers with opportunities to, for example, specify bid prices or ask prices for commodities. The bid and ask prices may be binding or non-binding. The system may also provide buyers and sellers with opportunities to set limit orders and market orders. Users may set limit orders to indicate the highest and lowest prices that the users wish to purchase or sell commodities for. Users may set market orders to indicate that they desire to purchase commodities at the next available market price. The system may provide pricing feedback to users using any suitable approach. The system may, for example, provide pricing feedback in real-time, near real-time, or delayed by a predefined amount of time (e.g., delayed fifteen minutes).  
      The system may, for example, provide a user with an opportunity to request the sale of a commodity that the user wholly or fractionally owns, at a price specified by the user. When the system receives a sale request for a fractionally-owned commodity, it may notify the other co-owners of the seller&#39;s request using any suitable approach. The system may, for example, notify the other co-owners when the system receives the sale request. In an alternative approach, the system may notify the other co-owners when a purchase request is matched (i.e., directly, by aggregation, by auction, etc.), with the sale request. Any other suitable approach may be used.  
      The system may notify other co-owners of the sale request, the seller&#39;s liquidity rights (if any), the co-owners&#39; options, or any suitable combination thereof. When, for example, a co-owner has periodic drag-along rights, the system may notify the co-owner whether the sale request is in accordance with those rights. The system may, for example, notify the other co-owners of their tag-along rights, if any. When co-owners do not have drag-along or tag-along rights, the seller may only sell his or her fractional interest in the commodity.  
      The system may also provide each co-owner with an opportunity to purchase the commodity, or aggregate a number of purchase requests of co-owners who wish to purchase the commodity. The system may provide co-owners with purchase opportunities prior to providing third parties with opportunities to purchase the commodity or the seller&#39;s fractional interest in the commodity. If no single co-owner or group of co-owners wishes to purchase the commodity, the system may: (1) attempt to match the seller&#39;s request with a pending purchase request and initiate transfer of ownership of a commodity or (2) initiate the transfer of ownership of a commodity to the originator of an already matched request. The system may attempt to match purchase and sale requests using any suitable approach. The system may attempt to match orders when, for example, orders are placed, at a predefined time each day, periodically, after a predefined number of orders have been placed, or with any other suitable frequency. A combination of these approaches may also be used.  
      Orders may be matched directly when, for example, the system finds a purchase request that matches a sale request in commodity type and price. Matches may also be made directly when, for example, a user selects a specific commodity that has already been offered for sale. The system may notify the buying and selling users, provide the users with opportunities to approve the transfer, and initiate the transfer of ownership of the commodity. When purchase and sale requests match with respect to commodity type but not price, the system may, for example, notify the buying and selling users and provide them with an opportunity to modify their requests. When the system finds trade requests that match in commodity types, the system may notify the trading users and initiate transfer of ownership of the commodities.  
      The system may also match purchase and sales requests by aggregating buyers, sellers, or both. The system may aggregate enough sales requests, for example, to fill one purchase request. The system may, for example, aggregate each of a number of units into a block commodity. The owners of each unit may retain their exclusive ownership over each unit, or the system may convert each user&#39;s interest in each unit into a fractional ownership in the block, and initiate the transfer of the entire block as one commodity to a buyer. In another approach, the system may initiate the transfer of ownership in each individual commodity from each seller to the buyer. If a seller of an individual commodity is a co-owner with drag-along rights, the system may initiate the transfer of the ownership rights of all of the co-owners to the buyer, or provide the co-owners with an opportunity to purchase the commodity. The system may aggregate purchase and sale requests on a by-time basis (i.e., on a first-come-first-serve basis).  
      The system may aggregate enough purchase requests to fulfill one or more sales requests. The system may, for example, transfer ownership in a single commodity to each purchaser of the aggregated order. When the commodity for sale is wholly owned, the system may initiate the transfer of ownership from the single seller of the commodity to each purchaser, giving each purchaser an equal fractional interest in the commodity. When the commodity for sale is owned fractionally by multiple co-owners without drag-along rights, the system may initiate the transfer of ownership from the seller of the commodity to each purchaser, giving each purchaser an equal fractional interest in the commodity. If the selling co-owner has drag-along rights, the system may initiate the transfer of ownership of all of the co-owners. If desired, the system may provide each buyer with drag-along rights, tag-along rights, or both, to attempt to maximize the liquidity of the sold commodity.  
      The system may also match orders by providing users with opportunities to initiate or participate in auctions for commodities. The system may provide a buyer with an opportunity to initiate an auction by, for example, allowing a buyer to indicate a price that the buyer is willing to pay for a particular type of fungible commodity or class of commodities (e.g., the buyer may indicate that he or she is willing to pay $100.00 for grain). Sellers may respond by bidding an amount of the requested commodity at the indicated price (e.g., 50 bushels for $100.00). The system may initiate the transfer of a commodity from a seller to the buyer when, for example, the seller offers the most amount of the commodity at the indicated price (e.g., 125 bushels for $100.00).  
      The system may also provide sellers with opportunities to auction commodities using any suitable approach. Seller based auctions may include, for example, English and Dutch style auctions, or any other suitable auction. In English style auctions, the system may start with a minimum bid and provide buyers with opportunities to bid higher and higher amounts until the highest bid is reached. In Dutch style auctions, the system may start with an asking price. As users purchase one or more commodities or units in a block commodity, the system may keep lowering the asking price until all of the available commodities or units are sold.  
      The system may notify co-owners that a selling co-owner has offered his or her fractional interest in a commodity for auction, and may allow the other co-owners to purchase the interest before allowing third parties to bid, or after the system has received the highest bid. The system may initiate a subauction, private to the co-owners, that allows only the co-owners to bid. Non-user co-owners (i.e., co-owners who are not registered users of the system) may participate, for example, by mail, telephone, fax, or computer (e.g., via e-mail). In another suitable approach, the system may allow other users to observe the bidding of the co-owners. When one or more co-owners do not purchase the selling co-owner&#39;s interest, the system may allow one or more third parties to purchase the interest. When the selling co-owner has drag-along rights, the system may allow third parties to bid for and purchase the fractional interests of all of the co-owners.  
      After matching purchase and sale orders between one or more co-owners and third parties directly, by aggregation, by auction, or using any other suitable approach, the system may drag the interests of the non-participating co-owners of the commodity into the transfer along with the selling co-owner&#39;s interest, pursuant to drag-along rights of the seller. The drag-along rights of the selling co-owner may have been originally part of the co-owner&#39;s original acquisition of the commodity or may have been agreed to by the co-owners as part of acquiring the commodity using the fractional ownership system. The system may automatically notify the non-participating co-owners of a potential sale and may provide the non-participating co-owners with an opportunity to purchase the entire commodity. If the other co-owners do not purchase the commodity, the selling co-owner is required to provide the fair market value of the commodity to the non-participating co-owners.  
      The system may generate necessary printed or electronic transfer documents (e.g., contracts of sale, co-ownership agreements, deeds, etc.), and provide the transfer documents to the sellers or buyers for physical or electronic execution. When a broker or attorney is required or needed for the transfer, such as for transfers of real property, the system may select a broker or attorney and generate any necessary retainer agreements. When the transfer documents and, if used, broker or attorney agreements have been executed by one side, that side may provide the documents to the other side using, for example, regular or electronic mail. When the documents have been signed by all parties, the system may provide for the electronic transfer of funds from a buyer or buyers to a seller or sellers. The system may remunerate non-participating co-owners for their interests first. The system may also provide for the electronic payment of brokers&#39; and attorneys&#39; fees. Once the necessary transfer documents have been executed and, in the case of a sale or renting, the necessary funds transferred, the system may record the transfer. The system may, for example, report the transfer with third parties such as governmental entities or title searchers for recordation.  
      The system may also provide users with opportunities to trade commodities. Users of the system may wish to trade, for example, temporal uses of co-owned property. The system may, for example, provide users with opportunities to enter trade requests for commodities the users own wholly or fractionally. The system may provide a user with, for example, an opportunity to specify the commodity or class of commodities that the user is trading, and to identify the particular commodity or class of commodities that the user wishes to trade for. The system may notify co-owners of the trading co-owner that the trading co-owner has indicated a desire to trade his or her interest in the commodity. The system may provide co-owners of a trading co-owner with opportunities to trade for or purchase the trading co-owner&#39;s interest in the commodity. This may be provided before providing trade or purchase opportunities to third parties if desired. The system may aggregate trade orders to effect trades if necessary.  
      The system may also perform maintenance actions. The system may, for example, provide co-owners with automatic notices of information of joint interest (e.g., maintenance schedule changes, maintenance fee changes, changes in conditions of membership in an ownership network, changes in liquidity, etc.). The system may, for example, provide co-owners with opportunities to schedule their uses of a commodity. The system may provide users with opportunities to place orders for renting other owners&#39; commodities or other co-owners&#39; shares in commodities (e.g., temporal use rights). Any other suitable maintenance action may be provided.  
      The system may be connected, via a suitable communications link, to another fractional ownership system, or to other types of ownership control systems (e.g., electronic time-share networks, utility producers, airlines, charter services, etc.). The interconnection of systems may allow for each system to contribute their commodities to other networks of commodities. Users may transfer their commodities between competing networks in attempts to maximize the value of participating in a particular network. This mobility of users between networks may tend to prompt networks to compete more because dissatisfied users could move commodities rather than having to sell their commodities at low prices to someone else tied to a single network.  
      Various features of the present invention may be illustrated by the following examples. A user who is a non-co-owner of a commodity may initiates a request to purchase a commodity, such as a 30 minute per week time share unit. A co-owner whose ownership is subject to an agreement with a right of first refusal and tag along rights may submit a matching asking price. The system may automatically notify other co-owners. If no-one is interested in buying the single 30 minute interest, so no one exercises the right of first refusal. However, five other co-owners, for example, exercise their tag along right by notifying the system. The system then notifies the buyer, who electronically notifies the system that he is willing to buy all six units. The system then sends out another notice to the co-owners. A second co-owner, who benefits from economies of scale, now is interested in the sale because he can use 3 hours of time more efficiently than just 30 minutes. Therefore, he exercises the right of first refusal electronically. The system notifies other co-owners, who acquiesce. The system awards the 6 units to the second co-owner at the price per unit previously agreed to by the bidder and the first co-owner. The system may generate all transfer documents, registers them, etc., and may transfer the purchase price electronically.  
      As another example, a user sells a share of Berkshire Hathaway in an auction in equal shares to 10 co-purchasers, including Jones, through the system. The system registers the share in the name of a custodian for the benefit of the 10 co-owners. Later, another user sells another share of Berkshire Hathaway through the system, and Jones purchases 90% of that share in the transaction. The system may detect that registering the second share as being 90% owned by Jones will leave him owning 100% of a single share, but split as fractional ownership of two different shares. Therefore, the system may automatically register the second share as fully owned by Jones, and may transfer ownership of his 10% interest in the first share to the users who had purchased the 10% interest in the second share.  
      As another example, fifty-one users each own a one week time share in a condominium in Florida, under an agreement in which the 52nd week is used for routine maintenance. A natural disaster damages the unit, requiring an additional week of maintenance. The system may automatically notify the co-owners of the needs. The system then determines who loses the week&#39;s use: one method would be to choose by lottery; another would be to have owners post how much they would be willing to take as payment for giving up their week—the system may solicit bids for the work if performed in those weeks (e.g., it may cost more to do the work during the winter than during the summer), choose the lowest combined price (cost of the week and cost of the work), and automatically schedule the cheapest combined week, notify the owners, pro rate the cost among the owners, add the cost to the next maintenance bill, and pay the proceeds electronically to the owner whose week was chosen.  
      As another example, a school teacher user posts a request to purchase a summer time share in an apartment in Manhattan, planning to spend the months off from teaching. No other users are interested in selling just such an interest. Later, another user who is a professor gets a job in Manhattan and posts a request to purchase an interest in an apartment for the fall through the spring. The system may automatically post the requests separately and together. A potential seller sees that together the two requests add up to a full year&#39;s interest in an apartment, and accepts the two requests. The system may close the purchase and sale with all of the documentation.  
      As still another example, an owner submits a request to sell all of her interest in an apartment, but notes that she is willing to sell as little as 75% of the interests in three month increments. Later, a user submits a request to buy an interest in the fall in an apartment meeting the general criteria of the seller&#39;s place. Later, another user submits a request to buy such an interest for the spring. Later, another user submits a request to buy such an interest for the winter. The system may automatically match the three buy requests with the minimum sales request, and executes the sale of the 9 months&#39; interests.  
      As still another example, Smith owns 5% of a share of Berkshire Hathaway, while Jones and Blake respectively own 1% and 5% of a second share. Both shares are subject to drag along rights. Smith and Jones notify the system that they plan to exercise their drag along rights, and the system matches a buyer who is willing to purchase one or two full shares (but no fractional shares). The system may sell both shares, notify co-owners, and electronically transfer the shares and the proceeds. Alternatively, in order to minimize the number of co-owners inconvenienced by an unwanted drag along, the system may first exchange Blake&#39;s and Smith&#39;s interests so that both sellers (Smith and Jones) own their interests in the second share. Then the system would sell only the second share, notify co-owners, and electronically transfer the share and the proceeds.  
      The fractional ownership system of the present invention may be implemented using, for example, a client/server based approach or, preferably, using an on-line approach. If desired, a combination of these approaches may be used. Illustrative on-line and client-server based arrangements for the fractional ownership system are shown in  FIGS. 1   a  and  1   b,  respectively. In the illustrative on-line arrangement of  FIG. 1   a,  Internet enabled access devices  200  may be connected via links  195  to Internet  210 . Internet enabled access devices  200  may include any device or combination of devices suitable for providing Internet access to a user of the time tracking system. Internet enabled access devices may include, for example, any suitable personal computer (PC), portable computer (e.g., a notebook computer), palmtop computer, handheld personal computer (H/PC), automobile PC, personal digital assistant (PDA), Internet-enabled cellular phone, combined cellular phone and PDA, set-top box (e.g., a Web TV enabled set-top box), or other device suitable for providing Internet access.  
      Internet server  215  may be any server suitable for providing on-line access to the fractional ownership system (e.g., a web server). Internet server  215  may, for example, provide one or more pages to Internet enabled access devices  200  using one or more suitable protocols (e.g., the HyperText Transfer Protocol (HTTP) and Transmission Control Protocol/Internet Protocol (TCP/IP)). The pages may be defined using, for example, any suitable markup language (e.g., HyperText Markup Language (HTML), Dynamic HyperText Markup Language (DHTML), Extensible Markup Language (XML), etc.). The pages may include scripts, computer code, or subsets of computer code, that define mini-programs (e.g., Per1 scripts, Java applets, etc.).  
      Links  195  may include any transmission medium suitable for providing Internet access to Internet enabled access devices  200 . Links  195  may include, for example, a dial-up telephone line, a computer network or Internet link, an infrared link, a radio frequency link, a satellite link, a digital subscriber line link (e.g., a DSL link), any other suitable transmission link or suitable combination of such links. Different links  195  may be of different types depending on, for example, the particular type of Internet access device  200 .  
      Any protocol or protocol stack suitable for supporting communications between Internet enabled access devices  200  and Internet server  215  over links  195  based on the particular device  200  and link  195  may be used. For example, Ethernet, Token Ring, Fiber Distributed Data Interface (FDDI), Circuit-Switched Cellular (CSC), Cellular Digital Packet Data (CDPD), RAM mobile data, Global System for Mobile communications (GSM), time division multiple access (TDMA), code division multiple access (CDMA), serial line Internet protocol (SLIP), point to point protocol (PPP), Transmission Control Protocol/Internet Protocol (TCP/IP), Sequenced Packet Exchange and Internetwork Packet Exchange (SPX/FPX) protocols, or any other suitable protocol or combination of protocols may be used.  
      Application server  170  may run any suitable database engine, such as, for example, Microsoft SQL Server, Oracle 8i, or some other suitable database engine. Application server  170  may maintain a database or databases, suitable to the database engine used, of information regarding users of the system and other third parties, commodities traded, and other aspects of the system, any suitable combination of which may sometimes be referred to herein as “system information.” As shown in  FIG. 1   a,  application server  170  may maintain commodity information database  175  and user information database  177 . Databases  175  and  177  have been shown as two separate databases. In practice, they may be a singe database or they may each include multiple databases.  
      Commodity information database  175  may include information regarding commodities traded by the system. Commodity information may be stored using any suitable database design (e.g., flat, relational, object oriented, etc.). Commodity information may include, for example, commodity identifiers, descriptions, units, owners, pending purchase, sale or trade requests, any other suitable information, or any suitable combination thereof. If desired, the system may associate users with various commodities by providing links between database  175  and database  177 .  
      User information database  177  may include information stored in a suitable database design (e.g., flat, relational, object oriented, etc.), regarding users of the system. User information database  177  may include, for example, user names, telephone numbers, addresses, company information, social security numbers, bank account information, credit card account information, any other information suitable to the system for performing system functions, or any suitable combination thereof. User information database  177  may also include information on additional parties, such as brokers and attorneys, that the system may select before initiating transfers. The system may provide users with opportunities to choose additional parties if desired.  
      Internet server  215  may retrieve system information from or provide system information to application server  170  using any suitable approach. Internet server  215  may, for example, have one or more common gateway interface (CGI) scripts for reading information submitted to Internet server  215  from application server  170  or from Internet enabled access devices  200 . One or more processes on Internet server  215  may, for example, generate SQL requests based on the information and provide the requests to application server  170 . In another suitable approach, Internet server  215  may invoke remote procedures that reside on application server  170  using one or more remote procedure calls. Application server  170  may execute, for example, SQL statements for such invoked remote procedures. In still another suitable approach, objects executed by Internet server  215  may communicate with objects executed by application server  170  using, for example, an object request broker (ORB). This may involve using, for example, Microsoft&#39;s Distributed Component Object Model (DCOM) approach. Any other suitable scheme may be used.  FIG. 1   a  shows Internet server  215  and application server  170  as separate servers. In practice, all or part of the functionality of the two servers may be combined into a single server.  
      Application server  170  and Internet enabled access devices  200  may be connected to electronic commerce system  140 , recordation system  180 , and transfer documents system  190  via Internet  210 . Alternatively application server  170  may be connected to these systems via a local area network, wide area network, or other link or combination of links (not shown).  FIG. 1   a  shows these systems as being separate from application server  170 . In practice the functions of application server  170  and one or more of these systems may be integrated into a single system.  
      Electronic commerce system  140  may include one or more computers that provide for the electronic debit of funds from user bank or credit card accounts, and may also allow for the electronic deposit of funds to user bank and credit card accounts. Electronic commerce may be accomplished using any suitable approach such as, for example, financial EDI (FEDI), electronic funds transfer (EFT), the Secured Electronic Transaction protocol (SET), the Joint Electronic Payments Initiative (JEPI), or any other suitable approach. In practice, the protocol stack used by the fractional ownership system may include secure protocols suitable to the chosen system implementation, such as, for example, secure HTTP (S-HTTP), secure mime (S/MIME), secure sockets layer (SSL), or any other suitable protocol or protocols.  
      Transfer documents system  190  may include one or more computers and other devices (e.g., printers, scanners, faxes, etc.) suitable for generating transfer documents and providing for the exchange of such documents. As used herein, transfer documents may include any document, physical or electronic, suitable is for effecting a transfer of a commodity between one or more users the system. This may include, for example, physical or electronic offers for sale, sales contracts, options, deeds and other documents of title, broker agreements, attorney retainer agreements, or any other suitable document. Electronic versions of these agreements may be maintained by transfer documents system as suitable files (e.g., PDF files). In one suitable approach, the system may associate various transfer documents with users, brokers or attorneys using a suitable database. When a particular user, broker, or attorney is involved in a transfer, the system may retrieve the electronically stored documents and provide them in printed form or electronically to the parties involved in the transfer.  
      In one approach, for example, transfer documents system  190  may, after receiving an order to transfer ownership in a commodity from one or more co-owners to another one or more potential co-owners, generate a printed contract of sale and send the contract to, for example, the buyer or buyers for execution. The buyers may sign the contract and send the contract to the seller or sellers for execution. The seller or sellers may sign the contract and send it back to the provider of transfer documents system  190 . In practice, the provider of transfer documents system  190  may not be the provider of application server  170 . The provider of transfer documents system  190  may scan in the document and electronically store it. After the transfer is complete, transfer documents system  190  may physically or electronically provide the transfer documents to recordation system  180 .  
      As a second example, transfer documents system  190  may provide electronic documents to the buyers and sellers. Buyers and sellers may, for example, access one or more web pages or other electronic documents that provide the buyers and sellers with opportunities to electronically transfer rights in one or more commodities. These web pages may be provided, for example, using a secure protocol such as S-HTTP, SSL, or some other suitable protocol or combination of protocols. Users may electronically sign the web pages using suitable digital signature technology. In an alternative approach, electronic documents may be exchanged as, for example, encrypted files (e.g., using Pretty Good Privacy (PGP)), encrypted e-mails (e.g., using S-MIME), or using any other suitable approach. After a transfer is complete, transfer documents system  190  may physically (e.g., by printing out and mailing) or electronically provide the transfer documents to recordation system  180 .  
      Recordation system  180  may include one or more computers and other devices (e.g., printers, scanners, faxes, etc.) suitable for recording the transfer of title for certain commodities for which recordation of title is required or permitted, such as, for example, for real property, intellectual property (e.g., patents, copyrights, trademarks, etc.) or other types of commodities. Recordation system  180  may be a system at a private entity that maintains databases of title information (e.g., the system provider, a real estate title searcher, etc.), at a governmental office that is responsible for recording chain of title for the commodities (e.g., town clerks&#39; offices, the assignment division of the United States Patent and Trademark Office, etc.), at some other entity, or a combination thereof (in which case there may be multiple recordation systems  180 ). Application server  170  may, in addition to or instead of recordation system  180 , record current owners of commodities or chains of titles by, for example, providing suitable fields in records within commodity information database  175 , or links between records within commodity information database  175  and user information database  177 .  
       FIG. 1   b  shows another illustrative arrangement for the fractional ownership system of the present invention. In the client/server arrangement of  FIG. 1   b,  personal computers  100  are interconnected via network  150  to application server  173 . Network  150  may be any suitable local area network (LAN), wide area network (WAN), or other suitable network. Personal computers, and their interconnection via networks, are well known. If desired, one or more personal computers  100  may be accessed by remote access device  120  to provide remote access to users to the system. Remote access device  120  may be any suitable device, such as a personal computer, personal digital assistant, cellular phone, or other device with remote access capabilities.  
      Application server  173  may run any suitable database engine, such as, for example, Microsoft SQL Server, Oracle 8i, or any other suitable database engine. Application server  173  may maintain commodity information database  175  and user information database  177 . Client applications running on personal computers  100  may allow users to enter user and commodity information, trade fractional ownership interests in commodities, and access other system features. The clients may, for example, pass SQL a requests as messages to server  173 . In another suitable approach, the client applications may invoke remote procedures that reside on server  173  using one or more remote procedure calls. Server  173  may execute SQL statements for such invoked remote procedures. In still another suitable approach, client objects executed by the client applications may communicate with server objects executed by server  173  using, for example, an object request broker (ORB). This may involve using, for example, Microsoft&#39;s Distributed Component Object Model (DCOM) approach. Any other suitable client/server based communications scheme may be used.  
      Electronic commerce system  140 , recordation system  180 , and transfer documents system  190  may be connected to application server  173  via links  185 . Links  185  may be any link suitable for providing communications between application server  173  and electronic commerce system  140 , recordation system  180 , and transfer documents system  190 . Links  185  may be, for example, computer network links, Internet links, telephone links, wireless links, or any other suitable link. In an alternative approach, electronic commerce system  140 , recordation system  180 , and transfer documents system  190  may be connected to network  150  via links suitable to the chosen network. The functions of application server  173  and one or more of electronic commerce system  140 , recordation system  180 , and transfer documents system  190  may be combined into a single system if desired.  
       FIG. 2  shows an illustrative, generalized arrangement for the Internet enabled access devices  200  of  FIG. 1   a.  Internet enabled access devices  200  may have, for example, user interface  210 , storage  220 , processing circuitry  230 , and communications device  240 . User interface  210  may be any suitable input device, output device, or combination thereof. User interface  210  may include, for example, a pointing device, keyboard, touch-pad, touch screen, pen stylus, voice recognition system, mouse, trackball, cathode ray tube (CRT) monitor, liquid crystal display (LCD), voice synthesis processor and speaker, or any other suitable user input or output device. Processing circuitry  230  may include any suitable processor, such an Intel Pentium® microprocessor, and other suitable circuitry (e.g., input/output (I/O) circuitry, direct memory access (DMA) circuitry, etc.). Storage  220  may be any suitable memory, storage device, or combination thereof, such as RAM, ROM, flash memory, a hard disk drive, etc. Communications device  240  may be any device suitable for supporting communications over links  195 . Communications device  240  may include, for example, a modem (e.g., any suitable analog or digital standard, cable, or cellular modem), network interface card (e.g., an Ethernet card, token ring card, etc.), wireless transceiver (e.g., an infrared, radio, or other suitable analog or digital transceiver), or other suitable communications device.  
       FIG. 3  is a flowchart of an overview of illustrative steps involved in providing users with access to various features of the fractional ownership control system of the present invention.  FIGS. 4-13  show illustrative flowcharts of steps involved in providing more specific aspects of the invention. The steps shown in  FIGS. 3-13  may be performed in any suitable order, based on, for example, the features provided by the system and its implementation. If desired, some of the steps may be deleted, and others added.  
      Some of the steps shown in  FIGS. 3-13  involve providing users with opportunities to interact with the system. Such steps may be performed by, for example, a client application that is programmed to generate or download screens suitable to provide such opportunities, by an Internet browser that downloads suitable pages to provide such opportunities, or using any other suitable approach. Other steps may involve additional processing, such as generating requests, matching requests, or other types of processing. In client/server arrangements, such processing may be performed by the client or the server, depending on the chosen system implementation and the degree to which the processing involves querying commodity information database  175  or user information database  177  ( FIG. 1   b ). In on-line arrangements, such processing may be performed by Internet enabled access device  200 , Internet server  215 , or application server  170  ( FIG. 1   a ), depending on, for example, the processing and storage capabilities of Internet enabled access device  200 , the chosen implementation for the markup language documents used, the degree to which the processing involves querying commodity information database  175  or user information database  177 , or other factors. For purpose of clarity, the following discussion will describe the steps shown in  FIGS. 3-13  as being performed by “the system,” which is intended to include any client/server or on-line arrangement suitable for performing the steps.  
      As shown in  FIG. 3 , the system may provide users with opportunities to access the system at step  300 . This may involve, for example, providing a user with a login page or screen (step  303 ), and obtaining a user ID and password from the user (step  305 ). If the person accessing the system is not a registered user, the system may provide the person with an opportunity to obtain a user ID and password (step  307 ).  
      After a user has accessed the system, the system may provide the user with opportunities to access various features of the system. If desired, the system may provide all users with access to all features of the system. Alternatively, the system may provide users with access to one or more subsets of all features, or all of the features, based on the users&#39; rights. User rights may be based on, for example, how much a user has paid to subscribe to the system, how many commodities the user manages, buys, sells, or trades with the system, or any other suitable criteria. The system may, for example, provide new users and existing users with opportunities to enter user information and to modify user information at step  320 . User information may include, for example, user names, telephone numbers, addresses, company information, social security numbers, bank account information, credit card account information, and any other information suitable to the system for performing system functions. User information may also include additional parties, such as, for example, brokers and attorneys, that, users may associate with their account for various types of transactions (e.g., obtaining financing, transferring real property, etc.).  
      The system may, for example, provide users with opportunities to enter commodity information (step  325 ). Users may desire to enter commodity information when, for example, users have ownership interests in commodities that the users have obtained without using the system, and wish to manage, sell, or trade using the system. The system may provide users with opportunities to enter, for example, commodity types, descriptions, units, co-owners, and other suitable information.  FIG. 4  shows a flowchart of illustrative steps involved in providing users with opportunities to enter commodity information. The system may, for example, prompt a user to enter the type of the commodity for which the user wishes to enter information (step  337 ). After the user enters the commodity type, the system may provide a specialized interface based on the type of commodity (step  339 ), and may prompt the user for additional commodity information (step  340 ).  
      The system may, for example, prompt users to provide photocopies or electronic copies, of transfer documents used to obtain the commodities (step  341 ). The system may receive electronic documents at step  343 . At step  347 , the system may receive paper documents. The system may, for example, scan in paper documents (step  349 ) and use suitable optical character recognition (OCR) software to obtain an electronically searchable document (step  351 ). The system may search the documents for information that may be useful to the system at step  355 . The system may, for example, search for co-owners&#39; names and other information so that the system may determine whether the co-owners are already users or not. If co-owners are not users, the system may target the co-owners with advertisements for the system in an attempt to register the co-owners (step  357 ) and allow them to participate in the features of the system. The system may determine, for example, if there are drag-along rights in the commodity. If so, the system may automatically generate a list of co-owners for use when there is a potential transfer in the ownership of the commodity. The system may store electronic documents for chain of title purposes.  
      Returning to  FIG. 3 , the system may provide users with opportunities to view commodity information at step  370 . This may include, for example, providing a specialized interface based on the commodity for which a user has indicated a desire to view commodity information (step  380 ). Specialized interfaces may make the system more user friendly and useful to the user because they provide information in a format optimized based on the commodity type for which information is displayed or other factors.  
      The system may also provide users with opportunities to purchase commodities, sell commodities, and trade commodities, at steps  390 ,  400 , and  410  respectively.  FIGS. 5, 6 , and  7  are flowcharts of illustrative steps involved in providing users with opportunities to purchase, sell, and trade commodities, respectively. As shown in  FIG. 5 , the system may provide a user with an opportunity to indicate a desire to purchase a commodity at step  500 . The system may provide users with this opportunity and other opportunities shown in  FIG. 5 , using any suitable user interface. The system may, for example, allow users to select a menu option from a menu, enter text, push a button, select a radio button, link, or other on-screen element, or provide any other suitable user interface. The system may prompt users for a commodity type at step  510 . Users may enter commodity types using any suitable interface element. The system may provide a specialized interface based, for example, on the commodity type entered by the user, at step  520 .  
      At step  530 , the system may provide users with opportunities to define a purchase request. The system may allow users to define purchase requests using any suitable approach. The system may, for example, provide a user with an opportunity to indicate a particular unique or fungible commodity (e.g., a particular piece of real estate, a particular patent, one or more shares of stock, one or more barrels of oil, etc.) at step  540 . The system may, for example, provide one or more drop-down lists, menus, searchable lists, check boxes, radio buttons, text fields, a combination of these elements, or any other suitable interface element or combination of elements, to provide this opportunity.  
      The system may provide a user with an opportunity to define a purchase request by, for example, defining a class of commodities (step  550 ). The class of commodities may be of the type provided to the system by the user at step  510 . The system may provide the user with an opportunity to define a class of commodities by, for example, selecting a class from a list of classes, defining a boolean or natural language expression, or using any other suitable approach. The system may, for example, provide one or more drop-down lists, menus, searchable lists, check boxes, radio buttons, text fields, a combination of these elements, or any other suitable interface element or combination of elements, to provide this opportunity.  
      The system may provide a user with an opportunity to specify a price within the purchase request (step  560 ). The price may be, for example, a bid price, market order, limit order, or any other suitable type of price. The system may, for example, provide one or more drop-down lists, menus, searchable lists, check boxes, radio buttons, text fields, a combination of these elements, or any other suitable interface element or combination of elements, to provide this opportunity.  
      The system may store purchase requests at step  570 . Purchase requests may be stored, for example, in commodity information database  175 , user information database  177 , in a separate database dedicated to storing purchase requests, using any suitable combination thereof, or using any other suitable approach.  
       FIG. 6  shows illustrative steps involved in providing users with opportunities to sell commodities (step  400  of  FIG. 3 ). The system may provide a user with an opportunity to indicate a desire to sell one or more commodities at step  600 . The system may provide users with this opportunity and other opportunities shown in  FIG. 6 , using any suitable user interface. The system may, for example, allow users to select a menu option from a menu, enter text, push a button, select a radio button, link, or other on-screen element, or provide any other suitable user interface element.  
      The system may prompt the user for a commodity type at step  610 . This may be performed by providing one or more drop-down lists, menus, searchable lists, check boxes, radio buttons, text fields, a combination of these elements, or any other suitable interface element or combination of elements. In response to a user indicating a commodity type, the system may provide a specialized interface based on, for example, the type of the commodity (step  620 ).  
      The system may provide a user with an opportunity to define one or more sales requests at step  630 . This may include, for example, providing a user with an opportunity to indicate one or more commodities that the user wishes to sell (step  640 ). The system may display the commodities that the user owns using any suitable approach. The system may, for example, display all of the commodities the user owns, sorted in any suitable order (e.g., alphabetically, by type, by purchase date, or any other suitable order), and allow the user to select or otherwise indicate a commodity or commodities that the user wishes to sell. The commodities displayed may be only those commodities of the type indicate by the user at step  610  if desired. The system may provide users with opportunities to define classes of commodities using boolean or natural language expressions.  
      Step  630  may also include providing a user with an opportunity to specify a price at which the user wishes to sell a commodity or commodities (step  640 ). The price may be, for example, an ask price, market order, limit order, or any other suitable type of price. The system may, for example, provide one or more drop-down lists, menus, searchable lists, check boxes, radio buttons, text fields, a combination of these elements, or any other suitable interface element or combination of elements, to provide this opportunity. The system may store sales requests that indicate commodities that users wish to sell, their quantities, prices, or any other suitable commodity information (step  650 ). Sale requests may be stored, for example, in commodity information database  175 , user information database  177 , in a separate database dedicated to storing purchase requests, any suitable combination thereof, or using any other suitable approach.  
       FIG. 7  shows illustrative steps involved in providing users with opportunities to trade commodities (step  410  of  FIG. 3 ). The system may provide users with opportunities to indicate a desire to trade one or more commodities at step  700 . The system may provide users with this opportunity and other opportunities shown in  FIG. 7 , using any suitable user interface. The system may, for example, allow users to select a menu option from a menu, enter text, click a button, select a radio button, link, or other on-screen element, or provide any other suitable user interface. The system may prompt users for a commodity type at step  710 . Users may enter commodity types using any suitable interface element. The system may provide a specialized interface based, for example, on the commodity type entered by the user, at step  720 . In practice, it may be desirable to omit steps  710  and  720  when, for example, the user wishes to trade one type of commodity for a different type of commodity.  
      At step  730 , the system may provide users with opportunities to define trade requests. The system may allow users to define trade requests using any suitable approach. Users define trade requests by, for example, indicating a commodity or commodities that the user fractionally or wholly owns and that a user wishes to trade (i.e., traded commodities). The user may also indicate a commodity or commodities that the user wishes to trade for (i.e., desired commodities). The system may, for example, provide a user with an opportunity to indicate a particular unique or fungible commodity (e.g., a particular piece of real estate, a particular patent, one or more shares of stock, one or more barrels of oil, etc.) that the user owns or desires at step  740 . The system may, for example, provide one or more drop-down lists, menus, searchable lists, check boxes, radio buttons, text fields, a combination of these elements, or any other suitable interface element or combination of elements to provide this opportunity.  
      The system may provide a user with an opportunity to define a trade request by, for example, defining classes of to-be-traded commodities that the user owns, classes of desired commodities that the user wishes to trade for, or both, at step  750 . Classes of to-be-traded or desired commodities may be limited to the commodity type provided to the system by the user at step  710 . The system may provide the user with an opportunity to define a class of commodities by, for example, selecting a class from a list of classes, defining a boolean or natural language expression, or using any other suitable approach. The system may, for example, provide one or more drop-down lists, menus, searchable lists, check boxes, radio buttons, text fields, a combination of these elements, or any other suitable interface element or combination of elements, to provide this opportunity.  
      The system may store trade requests that indicate to-be-traded and desired commodities at step  760 . Trade requests may be stored, for example, in commodity information database  175 , user information database  177 , in a separate database dedicated to storing purchase requests, any suitable combination thereof, or using any other suitable approach.  
      The system may initiate the transfer of ownership of commodities, or the trade of commodities (step  420  of  FIG. 3 ). An illustrative flowchart of steps involved in initiating the transfer of ownership in or trade of commodities is shown in  FIG. 8 . At step  800 , the system may attempt to match one or more purchase, sale, or trade requests. The system may it search for direct matches (step  810 ), construct aggregated matches (step  820 ), match by auction (step  830 ), or provide users with opportunities to match close requests (step  840 ).  
      The system may attempt to match requests directly (step  810 ) using any suitable approach. The system may attempt to match orders when, for example, orders are placed (i.e., defined by users and stored by the system), at a predefined time each day, periodically, after a predefined number of orders have been placed (i.e., defined by users and stored by the system), or with any other suitable frequency. A combination of these approaches may also be used. Matches may be performed for identified commodities (i.e., commodities identified at steps  540 ,  640 , and  740  of  FIGS. 5, 6 , and  7 , respectively) at step  813 , or for classes of commodities (i.e., classes defined at steps  550 ,  650 , and  750  of  FIGS. 5, 6 , and  7 , respectively) at step  817 . The system may find matches using any database query method suitable for the database in which the requests are stored (e.g., commodity information database  175 , user information database  177 , a combination thereof, or any other suitable database). When no direct matches are immediately found, the system may wait a user-defined or system-defined period of time (e.g., thirty days) until attempting to match the request again.  
      The system may also match requests by aggregating purchase requests, sale requests, or trade requests (step  820 ). The system may, for example, search a database (e.g., commodity information database  175 , user information database  177 , a combination thereof, or any other suitable database) for one or more requests for a particular commodity type and quantity (if applicable). The system may then aggregate the found requests to satisfy the original request that prompted the system to perform the search. The system may aggregate enough sales requests, for example, to fill one purchase request. The system may, for example, aggregate each of a number of units into a block commodity. The owners of each unit may retain their exclusive ownership over each unit and match all of the units to a single or aggregated purchase request. In another approach, the system may convert each user&#39;s interest in each unit into a fractional ownership in an entire block, and match the block to a single or aggregated purchase request. The system may aggregate requests on a by-time basis (i.e., on a first-come-first-serve basis).  
      The system may aggregate enough purchase requests to fulfill one or more sales requests. The system may also aggregate both sales requests and purchase requests to transfer ownership in one or more commodities. Matches may be performed for identified commodities (i.e., commodities identified at steps  540 ,  640 , and  740  of  FIGS. 5, 6 , and  7 , respectively) at step  823 , or for classes of commodities (i.e., classes defined at steps  550 ,  650 , and  750  of  FIGS. 5, 6 , and  7 , respectively) at step  827 . The system may find matches using any database query method suitable for the database in which the requests are stored (e.g., commodity information database  175  of  FIGS. 1   a  and  1   b ).  
      The system may also match purchase and sales requests by providing users with opportunities to initiate or participate in auctions for commodities (step  830 ). The system may provide users with opportunities to participate in or initiate auctions for identified commodities (i.e., commodities identified at steps  540 ,  640 , and  740  of  FIGS. 5, 6 , and  7 , respectively) at step  833 , or for classes of commodities (i.e., classes defined at steps  550 ,  650 , and  750  of  FIGS. 5, 6 , and  7 , respectively) at step  837 . Turning from  FIG. 8  to  FIG. 9 ,  FIG. 9  shows a flowchart of illustrative steps involved in providing users with opportunities to participate in or initiate auctions for identified commodities or classes of commodities (i.e., steps  833  and  837  of  FIG. 8 ). Some of the steps shown in  FIG. 9  may also be performed in connection with, for example, providing users with opportunities to directly participate in or initiate electronic auctions in general, or, to automatically participate in auctions when the system does not find matches for pending purchase or sale requests.  
      The system may provide a user with an opportunity to indicate a desire to participate in an electronic auction, or to initiate an electronic auction, at step  900 . In response to a user indicating a desire to participate in an auction or to initiate an auction, the system may provide the user with an opportunity to define an auction request (step  910 ). The system may provide the user with an opportunity to, for example, indicate a particular unique or fungible commodity (e.g., a particular piece of real estate, a particular patent, one or more shares of stock, one or more barrels of oil, etc.) that the user owns or desires. The system may, for example, provide one or more drop-down lists, menus, searchable lists, check boxes, radio buttons, text fields, a combination of these elements, or any other suitable interface element or combination of elements to provide this opportunity.  
      The system may provide a user with an opportunity to define an auction request by, for example, defining classes of commodities that the user owns and wishes to auction, defining classes of desired commodities that the user wishes to auction for, or both. The system may provide the user with an opportunity to define a class of commodities by, for example, selecting a class from a list of classes, defining a boolean or natural language expression, or using any other suitable approach. The system may, for example, provide one or more drop-down lists, menus, searchable lists, check boxes, radio buttons, text fields, a combination of these elements, or any other suitable interface element or combination of elements, to provide this opportunity.  
      In response to the user having indicated a desire to participate in an auction at step  900 , the system may attempt to find a matching auction at step  940 . The system may attempt to find a matching auction by, for example, searching a suitable database (e.g., commodity information database  175 , user information database  177 , a combination thereof, some other database which may be dedicated to storing requests, etc.) for pending or active auctions. If there is a matching auction, the system may provide the user with an opportunity to participate in the auction (e.g., accept bids, make counter offers, make bids) at step  950 . If there is no matching auction, the system may store the auction request until there is a matching purchase, sale, or auction request.  
      In response to a user having indicated a desire to initiate an auction at step  900 , the system may initiate an auction at step  920 . The system may initiate an auction by, for example, searching a suitable database (e.g., commodity information database  175  or user information database  177 , a combination thereof, some other database which may be dedicated to storing requests, etc.) for unmatched purchase or sale requests that match the auction request. The system may provide the user with an opportunity to participate in the auction (e.g., accept bids, make counter offers, make bids) at step  950 .  
      The system may provide a buyer with an opportunity to participate in the auction by, for example, allowing a buyer to indicate a price that the buyer is willing to pay for a particular type of fungible commodity or class of commodities (e.g., the buyer may indicate that he or she is willing to pay $100.00 for grain) (step  950 ). Sellers may respond by bidding an amount of the requested commodity at the indicated price (e.g., 50 bushels for $100.00). The system may complete the auction (step  960 ) and initiate the transfer of ownership in a commodity from a seller to the buyer when, for example, the seller offers the most amount of the commodity at the indicated price (e.g., 125 bushels for $100.00).  
      The system may also provide sellers with opportunities to participate in auctions at step  950 . Sellers may auction commodities using any suitable open or closed auction approach. Seller based auctions may include, for example, English and Dutch style auctions, or any other suitable auction. In English style auctions, the system may start with a minimum bid and provide buyers with opportunities to bid higher and higher amounts until the highest bid is reached. In Dutch style auctions, the system may start with an asking price. As users purchase one or more commodities or units in a block commodity, the system may keep lowering the asking price until all of the available commodities or units are sold.  
      The system may provide users with opportunities to participate in or initiate auctions when, for example, there are no matches for the users&#39; pending purchase or sale requests. The system may, for example, search for direct matches, or aggregate matches, at steps  810  and  820  of  FIG. 8 , collectively represented in  FIG. 9  as step  930 . When the system finds no direct or aggregated matches for a particular request, the system may attempt to find a matching auction at step  940 . When a matching auction is found, the system may provide the user with an opportunity to participate in the auction at step  950 . When a matching auction is not found, the system may store the original purchase or sales request at step  970  until there is a match. In another suitable approach, the system may attempt to continue trying to find a direct or aggregate match for a user-defined or system-defined period of time (e.g., six months) before initiating an auction.  
      Returning to  FIG. 8 , the system may also match requests by providing users with opportunity to match close requests. The system may, for example, find one or more requests that approximately match an original request (i.e., the request that prompted the system to perform the searches at steps  810  or  820 ) in commodity type, quantity, price, or any suitable combination thereof, within a predefined threshold. The predefined threshold may be designated by the system, or the system may provide users with opportunities to enter user preferences or rules (e.g., boolean or natural language expressions) that indicate suitable thresholds for close matches. The system may provide a user with close requests, and provide the user with an opportunity to match the original request to a close request. This opportunity may be provided using any suitable approach. The system may provide the user with an opportunity to select a close request, or indicate a desire to conform an original request to a close request, using push buttons, radio buttons, drop-down menus, text fields, or any other suitable user interface element.  
      The system may determine whether there are co-owners of a purchased, sold, or traded commodity at step  850 . Step  850  may be performed by the system at any suitable time during the initiation of the transfer of ownership of a commodity (i.e., step  420  of  FIG. 3 ). When the system provides a sale, for example, the commodity or class of commodities that is the subject of the sale may be indicated by the user as part of a sales request or similar auction request. The system may determine whether there are any co-owners associated with the commodity before matching the sales request with a purchase request. When the system provides a purchase, the commodity or class of commodities that is the subject of the purchase may not be indicated until the purchase request is matched. Co-owners may not be determined until a match has occurred.  
      The system may determine whether there are co-owners associated with a commodity using any suitable approach. The system may, for example, reference pointers to owners associated with a commodity (e.g., links to records in user information database  177  of  FIGS. 1   a  and  1   b ) from commodity records in commodity information database  175  ( FIGS. 1   a  and  1   b ). In another approach, the system may search user information database  177  for owners associated with the commodity (e.g., by links to commodity information database, commodity identifiers, etc.). A combination of these approaches or any other suitable approach may be used. When a commodity is co-owned, or will be co-owned, the system may address the co-owners&#39; rights at step  860 . When the commodity is wholly owned before and after the purchase or sale, the system may proceed to perform additional functions related to the transfer of ownership in the commodity (e.g., steps  460 - 480  of  FIG. 3 ).  
       FIG. 10  shows a flowchart of illustrative steps involved in addressing co-ownership rights in the contexts of purchases, sales, and trades. In particular, the system may address drag-along or tag-along rights that have been associated with a commodity that was fractionally owned prior to a purchase, sale, or trade, or that will be fractionally owned after a purchase, sale, or trade. The system may determine whether drag-along or tag-along rights apply to a commodity at step  1000 . When drag-along or tag-along rights apply, the system may notify other co-owners of the commodity that is being purchased or sold (step  1010 ). The system may notify other co-owners when, for example, a purchase or sale request is defined, when a purchase or sale request is matched (i.e., directly, by aggregation, by auction, matched to a trade request, etc.), or at any other suitable time. The system may notify co-owners using any suitable approach. The system may, for example, send user and non-user co-owners e-mails, provide messages from within system display screens or web pages to user owners, provide web pages to non-user co-owners, print out letters that are mailed to the co-owners, or use any other suitable approach to notify user and non-user co-owners. In the illustrative steps of  FIG. 10 , the system may not notify co-owners of commodities for which there are no associated drag-along or tag-along rights as indicated by the solid line from step  1000  to step  460 . If desired, the system may notify such co-owners to provide them with opportunities to participate in a purchase or sale (e.g., by auction), as indicated by the dotted line to step  1010 .  
      The system may notify other co-owners of any suitable commodity or user information such as, for example, sale request information, the seller&#39;s liquidity rights (if any), co-owners&#39; rights, or any suitable combination thereof. When, for example, a co-owner has periodic drag-along rights, the system may notify the users of whether the sale request is in accordance with those rights. The system may, if applicable, notify co-owners of their tag-along rights, if any, along with any other suitable information (e.g., purchase request information).  
      The system may also provide co-owners with an opportunity to purchase the commodity directly by aggregation, by auction, or using any other suitable approach. The system may provide co-owners with purchase opportunities prior to providing third parties with opportunities to purchase the commodity or the seller&#39;s interest in the commodity. If no single co-owner or group of co-owners wishes or wish to purchase the commodity, the system may: (1) attempt to match the seller&#39;s request with a purchase request if the system notified the other co-owners of a sale prior to a match, or (2) continuing with the transfer of ownership if a match has already occurred.  
      The system may provide non-user co-owners with opportunities to purchase the commodity using any suitable approach. The system may, for example, allow non-users to participate, and provide information to non-users, via e-mail, an accessible web page, telephone, facsimile, mail, or using any other suitable approach. When non-users participate by mail or fax, a system operator may enter the non-user&#39;s bid or lack of a bid into the system.  
      The system may provide co-owners with opportunities to sell their co-ownership interests at step  1030 . This may be as a result of the co-owners having tag-along rights (step  1035 ). The system may provide non-user co-owners with opportunities to sell their co-ownership interests using any suitable approach. The system may, for example, allow non-users to participate, and provide information to non-users, via e-mail, an accessible web page, telephone, facsimile, mail, or using any other suitable approach. When non-users participate by mail or fax, a system operator may enter the non-user&#39;s bid or lack of a bid into the system.  
      When one or more co-owners indicate a desire to exercise their rights, the system may provide a prospective purchaser (if a match has already occurred) with an opportunity to accept the purchase of those interests at step  1040 . When the user refuses to purchase the additional co-ownership interests, the system may cancel the sale or purchase (depending on whether the co-owner issued a sales request or the purchaser issued a purchase request, respectively) at step  1045 . If the purchaser indicated a desire to purchase the co-ownership interests, the system may continue the transfer and generate appropriate transfer documents (e.g., step  460  of  FIG. 3 ).  
      Once the system has initiated the transfer of ownership as described herein, the system may generate and provide transfer documents at step  460  of  FIG. 3 .  FIG. 11  is a flowchart of illustrative steps involved in generating and providing transfer and other documents. The system may determine whether a third party, such as a real estate broker, attorney, or mortgage broker, is required for a transfer, such as for transfers of real property. The system may select a third party (step  1100 ) either automatically, or by providing a user with an opportunity to select the third party (step  1105 ).  
      At step  1110 , the system may generate any transfer documents and necessary retainer or other agreements. Transfer documents may include, for example, physical or electronic offers for sale, sales contracts, options, deeds and other documents of title, broker agreements, attorney retainer agreements, or any other suitable document. Transfer documents may also include, for example, trade documents and rental agreements that provide the right to use a commodity without transferring title. Electronic versions of these agreements may be maintained by the system as suitable files (e.g., PDF files). In one suitable approach, the system may associate various transfer documents with users, brokers, or attorneys using a suitable database. When a particular user, broker, or attorney is involved in a transfer, the system may retrieve the electronically stored documents and provide them in printed form or electronically to the parties involved in the transfer for signature (step  1120 ). Users and non-user co-owners may read electronic documents in their electronic format or may print the documents out.  
      The system may provide documents electronically using any suitable approach. The system may, for example, e-mail documents to users and non-user co-owners. In another suitable approach, the system may provide parties with e-mails containing links (e.g., hyperlinks) that users may select to launch suitable software (e.g., a web browser) to access the documents. In still another suitable approach, the system may allow users to browse transfer documents while in the system. When documents are provided electronically, the system may provide parties with an opportunity to electronically sign the documents using any suitable electronic signatures technology (step  1130 ). The system may, for example, provide documents to parties via e-mail so that the users can sign the documents electronically from their access devices or computers. Any other suitable approach or combination of approaches may be used. Users and non-user co-owners may also, for example, print out electronic documents and sign the printout. The system may obtain documents at step  1140 . This may include, for example, receiving electronically signed electronic documents. This may also include, for example, receiving physical documents and converting them to an electronic format.  
      Returning to  FIG. 3 , the system may provide for the electronic exchange or transfer of remuneration for commodities sold or purchased (step  470 ). The system may remunerate non-participating co-owners for their interests first. Funds may be transferred between buyers&#39; and sellers&#39; accounts, between an owner and renter&#39;s accounts, or between traders&#39; accounts. The system may also provide for the electronic payment of brokers&#39; and attorneys&#39; fees. Electronic commerce may be accomplished using any suitable approach such as, for example, financial EDI (FEDI), electronic funds transfer (EFT), the Secured Electronic Transaction protocol (SET), the Joint Electronic Payments Initiative (JEPI), or any other suitable approach.  
      The system may record the transfer of title in commodities at step  480 . The system, via a suitable communications network, may record the transfer at a private entity who maintains databases of title information (e.g., the system provider, a real estate title searcher, etc.), at a governmental office that is responsible for recording chain of title for the commodities (e.g., town clerks&#39; offices, the assignment division of the United States Patent and Trademark Office, etc.), at some other entity, or a combination thereof. The system may also record the transfer by, for example, providing suitable fields in records within commodity information database  175 , or links between records within commodity information database  175  and user information database  177  ( FIGS. 1   a  and  1   b ), to indicate the transfer. If the new or previous owner or owners were not users of the system, the system may attempt to target them with advertisements to entice them to become a user.  
       FIG. 12  is a flowchart of illustrative steps involved in providing owners and co-owners with information regarding changes in commodity information. Changes in commodity information may include, for example, changes in maintenance schedules, changes in maintenance fees, changes in conditions of membership in an ownership network, changes in liquidity, or any other information regarding changes in commodity information. An entity associated with a commodity may, for example, determine that these or other changes are necessary or desirable. The entity, such as a management corporation, maintenance corporation, co-owner, or any other interested entity, may be a user of the system. The system may provide such an entity with an opportunity to change commodity information at step  1200 . The system may notify the owner or co-owners of a commodity (which may include non-user co-owners) of the change in information using any suitable approach (step  1210 ). The system may, for example, send owners and co-owners e-mails or regular mail (i.e., by printing out a message that is mailed by the system provided or other entity). The system may also provide messages within display screens or web pages. Any other suitable approach may be used.  
       FIG. 13  is a flowchart of illustrative steps involved in providing users with opportunities to transfer commodities between networks of commodities. Users may wish to transfer commodities between networks to, for example, obtain lower operational, management, maintenance, or other costs, to increase the liquidity or value of a commodity, or for other reasons. At step  1300 , the system may provide a user with an opportunity to indicate a desire to transfer a commodity to a different network. In response to a user indicating such a desire, the system may provide the user with an opportunity to indicate the network to which the user wishes to transfer a commodity. The system may provide this opportunity using, for example, drop-down menus, searchable lists, buttons, radio buttons, text fields, or any other suitable user interface element.  
      If the commodity is co-owned, the system may notify the other co-owners of the proposed transfer at step  1320 . The system may notify the other co-owners by, for example, sending e-mails, regular mails, system messages (if the other co-owners are users), or using any approach suitable for notifying the other co-owners. The system may provide the other co-owners with an opportunity to vote on the transfer at step  1320 . User co-owners may vote via the system. Non-user co-owners may vote via e-mail, regular mail, fax, or telephone, any of which may be indicated as available to the non-user co-owners within the notification from the system. If desired, the system may include sufficient hardware and software to provide for automatic voting over the telephone.  
      When a sufficient number of affirmative votes of the co-owners (e.g., a majority, two-thirds, etc.) is received, the system may transfer the commodity to the indicated network at step  1340 . When an insufficient number of affirmative votes are received, the system may provide all of the co-owners with an opportunity to submit an alternate network (e.g., via e-mail, mail, phone, fax, etc.) (step  1335 ). In practice, steps  1330  and  1335  may be combined. Voting may continue using any suitable approach to determine whether there is a preferred network. The system may, for example, provide for voting in rounds. Each co-owner may be provided with an opportunity to identify an alternate network in the first round. In each subsequent round, the network with the least number of votes is removed from consideration. If the last network to remain does not receive a sufficient amount of affirmative votes, the system notifies all co-owners that voting has terminated and that a transfer will not take place. When a network receives a sufficient number of votes, the system may transfer the commodity to the new network (step  1340 ).  
      The system may transfer the commodity to the indicated network, which is also the winning network when a vote has taken place, at step  1340 . This may be accomplished using any suitable approach. When the new network is serviced by a system in accordance with the present invention, then the transferring system may transfer user and commodity information associated with the co-owners and the commodity to the receiving system. The transferring system may, if desired, retain a copy of the information. When the new network is not serviced by a system in accordance with the present invention, the transferring system may transfer information in a suitable universal file format (e.g., a comma delimited text file, a tab delimited text file, as SQL records or as an SQL database, as an HTML or other markup language file, etc.) to the receiving system using any suitable approach (e.g., e-mail, the File Transfer Protocol (FTP), etc.). In still another suitable approach, the system may be programmed to provide the user and commodity information in a proprietary format readable by the receiving system.  
      The features of an electronic ownership control system in accordance with the present invention may be presented to users using any graphical user interface suitable to the chosen client/server or on-line approach used to implement the system.  FIGS. 14-49  show an illustrative graphical user interface for an electronic ownership control system in accordance with the present invention. For purposes of clarity,  FIGS. 14-49  will be described as illustrative web pages for use in an on-line electronic ownership control system. The interface shown may, in practice, be used as suitable display screens in a client/server based system.  
      The illustrative web pages shown in  FIGS. 14-49  illustrate features of the system as they may be used to provide users with opportunities to manage and transfer ownership in a number of types of commodities. The types of commodities shown in the following figures are only illustrative examples. The features of the system of the present invention may be used to provide users with opportunities to manage and transfer ownership in any other commodity as defined previously herein. Moreover, the user interface elements shown in the figures are only illustrative, and may be replaced with any other user interface elements suitable for the features with which the illustrative interface elements are associated.  
      An illustrative login page  1400  in accordance with the present invention is shown in  FIG. 14 . Login page  1400  and other pages of the system may include, for example, advertisements  50  and links to additional features (e.g., link  1410 ). Advertisements  50  may be any suitable text, graphic, or video advertisement.  FIGS. 14-49  illustrate the use of two advertisements  50  within each page. In practice, pages may include zero, one, two, or more than two advertisements if desired. Advertisements  50  may have associated audio. Pure audio advertisements may be played without displaying visual indicators of their availability if desired. Login page  1400  also includes text boxes  1415  that provide users with opportunities to enter a login ID and a password. Users may indicate they have entered their information by, for example, pressing button  1420 . In response, the system may display a portfolio page. An illustrative portfolio page  1500  is shown in  FIG. 15  and is discussed below.  
      Page  1400  may include link  1410  to provide those who are not users an opportunity to register with the system. In response to, for example, the user selecting link  1410 , the system may provide a blank user information page, such as illustrative user information page  1500  of  FIG. 15 . User information page  1500  of  FIG. 15  may provide new users an opportunity to input new user information in, for example, a number of text boxes. The system may prompt for, for example, a user&#39;s full name, address, telephone number, business address and phone number, e-mail address, social security number, bank account information, credit card account information, or any other suitable information. In response to a new user indicating that all of the necessary information has been entered (e.g., by pressing button  1510 ), the system may provide the user with an opportunity to enter other related information, such as associated party information and commodity information, or to access other system features. The system may require the new user to re-login into the system before entering this information or accessing additional features. The user may re-login into the system by, for example, issuing suitable navigation commands with a web browser (e.g., pressing a “back button,” closing the browser and restarting it, or any other suitable approach). Alternatively, the system may provide a button, link, or other interface element providing the user with an opportunity to re-login into the system.  
      Turning to  FIG. 16   a,  the system may provide portfolio page  1600  in response to a user logging into the system. Portfolio page  1600 , and other pages of the system, may include links that provide users with opportunities to access various features of the system. Users may select link  82  to, for example, view or edit user information. Users may select link  84  to, for example, view, enter, or edit information regarding parties associated with the user. Users may select link  86  to, for example, view, enter, or edit commodities information. Users may select links  88 ,  90 , and  92  to purchase, sell, and trade commodities, respectively. Users may select link  94  to access maintenance or other features. Users may select link  96  to view or send messages.  
       FIG. 16   b  shows an illustrative user information page  1501  that the system may display in response to a user selecting link  82 . User information page  1501  of  FIG. 16   b  is a completed version of the blank user information page  1500  of  FIG. 15 , and includes elements for providing a user with an opportunity to edit his or her user information.  
       FIG. 17  shows an illustrative associated parties page  1700  that the system may provide in response to a user indicating a desire to enter associated party information by, for example, selecting associated parties link  84 . Associated parties page  1700  may include links or other suitable interface elements that provide users with opportunities to view information regarding attorneys, real estate brokers, mortgage brokers, or friends. Other types of third parties may be associated with users if desired (e.g., stock brokers, engineers, title searchers, or any other party suitable to the types of commodities handled by the system). In response to a user selecting attorneys link  1705  for example, the system may provide the user with an attorneys page that provides the user with opportunities to view, enter or edit information for attorneys associated with the user. An illustrative attorneys page  1800  is shown in  FIG. 18 . Attorneys page  1800  may include links for each attorney associated with a user.  
      In the example of  FIG. 18 , the user has only one associated attorney. In response to the user selecting that attorney (e.g., by selecting the attorney&#39;s link), the system may provide an attorney information page, such as illustrative attorney information page  1900  of  FIG. 19 . Attorney information pages may provide users with opportunities to view and edit attorney information. The system may provide attorney information page  1900  as a blank template to the user in response to the user indicating a desire to add an attorney (e.g., by selecting link  1805  of  FIG. 18 ). Page  1900  may also be changed, for example, to include interface elements suitable for providing users with opportunities to enter information into the fields of the page (e.g., drop-down lists, searchable lists, browse buttons, etc.).  
      Attorney information page  1900  may also provide users with opportunities to view documents (or add documents) related to an attorney. In the example, of  FIG. 19 , the shown attorney has two related documents, a retainer agreement and a contract of sale. A user may indicate a desire to view a related document by, for example, selecting the document&#39;s link. In response, the system may provide the document for viewing by the user. In practice, the user&#39;s web browser may launch a viewer suitable for displaying the document (e.g., a Microsoft Word viewer, an Adobe Acrobat viewer, etc.). The system or the viewer may provide the user with an opportunity to print the related document.  
      Returning to  FIG. 17 , users may select link  1710  to view, enter, or edit information for real estate brokers associated with the user. In response to a user selecting link  1710 , the system may provide a brokers screen. An illustrative brokers screen  2000  is shown in  FIG. 20 . Brokers screen  2000  may include, for example, a list of brokers associated with the user. In the example, of  FIG. 20 , there is only one broker associated with the user. In response to the -user selecting a broker (e.g., by selecting a link associated with a broker), the system may provide a real estate broker information page. Real estate broker information pages, such as illustrative real estate broker information page  2100  of  FIG. 21 , may provide the user with an opportunity to view or edit information for a real estate broker. The system may provide real estate broker information page  2100  as a blank template with suitable interface elements to the user in response to the user indicating a desire to add a real estate broker (e.g., by selecting link  2005  of  FIG. 20 ). Real estate broker information page  2100  may also provide users with opportunities to view documents (or add documents) related to a real estate broker. In the example of  FIG. 21 , the shown real estate broker has one related document, a broker agreement. A user may indicate a desire to view the broker agreement by, for example, selecting the document&#39;s link.  
      Returning to  FIG. 17 , users may select link  1715  to view, enter, or edit information for mortgage brokers associated with the user. In response to a user selecting link  1715 , the system may provide a mortgage brokers page. An illustrative mortgage brokers page  2200  is shown in  FIG. 22   a.  Mortgage brokers page  2200  may include, for example, a list of mortgage brokers associated with the user that is organized or sorted in any suitable format. In the example of  FIG. 22   a,  there are two mortgage brokers associated with the user. In response to the user selecting a mortgage broker (e.g., by selecting a link associated with a broker), the system may provide a mortgage broker information page. Mortgage broker information pages, such as illustrative mortgage broker information page  2250  of  FIG. 22   b,  may provide the user with an opportunity to view or edit information for a mortgage broker. The system may provide mortgage broker information page  2250  as a blank template with suitable interface elements to the user in response to the user indicating a desire to add a mortgage broker (e.g., by selecting link  2210  of  FIG. 22   a ). Mortgage broker information page  2250  may also provide users with an opportunity to view documents (or add documents) related to a mortgage broker. In the example of  FIG. 22   b,  the shown mortgage broker has one related document, a pre-approval letter. A user may indicate a desire to view the pre-approval letter by, for example, selecting the document&#39;s link.  
      Returning to  FIG. 17 , users may select link  1720  to view, enter, or edit information for friends associated with the user. Friends may be associated with a user for any suitable purpose within the system. Friends may be, for example, user or non-user co-owners of properties. Friends may also be users or non-users of the system that a user may wish to want to involve in splits—opportunities to join the user in a purchase, trade, or ownership of a commodity. A user may wish to split a commodity when, for example, the user cannot or does not desire to purchase or trade for a commodity alone. The system may provide the user with an opportunity to notify friends of the opportunity and ask them if they want to participate in the purchase or trade. A user may also wish to split a commodity when, for example, the user does not need or desire all of a commodity the user owns. The user may wish to provide friends with an opportunity to purchase some of the commodity.  
      In response to a user selecting link  1720 , the system may provide a friends page. An illustrative friends page  2300  is shown in  FIG. 23   a.  Friends page  2300  may include, for example, a list of friends associated with the user that is organized or sorted in any suitable format. In the example of  FIG. 23   a,  there are two friends associated with the user. In response to the user selecting a friend (e.g., by selecting a link associated with the friend), the system may provide a friend information page. Friend information pages, such as illustrative friend information page  2350  of  FIG. 23   b,  may provide the user with an opportunity to view or edit information for a friend. The system may provide friend information page  2350  as a blank template with suitable interface elements to the user in response to the user indicating a desire to add a friend (e.g., by selecting link  2310  of  FIG. 23   a ).  
      Friend information page  2350  may indicate, or provide users with opportunities to indicate, commodities that are co-owned by the user and the friend. The user may indicate a desire to view information about the co-owned commodity by, for example, selecting its link. In response, the system may provide a commodity information page, such as the illustrative commodity information page  3000  shown in  FIG. 30   a.    
      Returning to  FIG. 16   a,  the system may provide users with opportunities to enter information for commodities that the users acquired without using the system, and may allow the users to manage the commodities using the system. A user may indicate a desire to enter commodity information by, for example, selecting commodities link  86  from  FIG. 16   a  or any page that includes link  86 . In response, the system may provide, for example, a type selection page, such as illustrative type selection pages  2400  of  FIGS. 24   a  and  25   a.  In the examples of  FIGS. 24   a  and  25   a,  the user has chosen a commodity type of utilities/electrical and real estate/vacation, respectively. These are just two examples, as the system may provide users with opportunities to add commodities of any type as defined herein.  
      The type selection pages of  FIGS. 24   a  and  25   a  include a drop-down list that prompts a user for a commodity type. From this type, the system may provide specialized pages within which the user may enter commodity information. This example of one type of specialization of pages is illustrated when comparing the illustrative pages of  FIGS. 24   a - 24   c  for commodities of type utilities/electrical, and the illustrative pages of  FIGS. 25   a - 25   c  for commodities of type real property/vacation. Specialization may not be used if it is not desired.  
      The system may, in response to a user selecting a commodity type of utilities/electrical as shown in  FIG. 24   a,  provide a commodities information page. Commodities information pages may only provide interface elements for information relevant to the commodity type selected or otherwise indicated by the user. An illustrative commodities information page for commodities of type utilities/electrical is shown in  FIG. 24   b.  In this example, the system may prompt the user for the name of the source of the electricity, the dates between which the user owns output from the source, the amount of output, the price paid, or any other suitable information. Commodities information pages may prompt for whether there are drag-along or tag-along rights associated with a commodity, and may provide users with opportunities to access additional pages for inputting information using interfaces designed especially for the selected commodity type. In this example, the system may provide users with an opportunity to define the hourly consumption of the user within each day of output that may have been used to obtain the commodity.  
      In response to a user indicating a desire to define the user&#39;s hourly consumption (e.g., by selecting link  2455 ), the system may provide an hourly consumption page. An illustrative hourly consumption page  2470  is shown in  FIG. 24   c.  In practice, it may be desirable to design interfaces in accordance with accustomed or widely accepted electronic or non-electronic formats for defining commodities within an industry. For example, it may be desirable to design pages within the system to look like standardized forms. In this example, the user is provided with an interactive bar graph to define the user&#39;s hourly consumption. The user may select and move a bar  2472  to indicate the amount of output the user requires during a given time slot.  
      The system may, in response to a user selecting a commodity type of real estate/vacation as shown in  FIG. 25   a,  provide illustrative ownership selection page  2550  of  FIG. 25   b.  Ownership selection pages may be desirable when, as with vacation property, there may be a number of possible different forms of ownership for a type of commodity. The system may provide specialized pages based on the type of ownership. In the example of  FIG. 25   b,  the user has selected a deeded-week form of ownership. In practice, it may be undesirable to provide specialized pages for commodities that do not have a number of types of possible ownership.  
      An illustrative commodities information page  2552  for deeded-week vacation properties is shown in  FIG. 25   c.  The system may prompt the user to enter, for example, the name of the provider or manager of the property, its location, the week of ownership, the network of properties with which the property is associated (which may be provided using a predefined list of networks), the price paid, whether there are drag-along or tag-along rights, or any other suitable information. Commodities information pages or other pages for commodities in general, and in this example, may provide users with opportunities to generate or access a list of co-owners associated with a commodity, and to associate additional documents with a commodity.  
      In response to a user indicating a desire to generate or access a list of co-owners associated with a property (e.g., by selecting link  2570  of  FIG. 25   c ), the system may provide a co-owners page. An illustrative co-owners page  2600  is shown in  FIG. 26 . The system may already have a list of co-owners associated with the property. Such a list may, for example, have been entered by another co-owner, have been generated by the system from the system information, or may have been electronically or otherwise provided to the system or provider of the system from the network of properties associated with the property. The system may provide the user with an opportunity to edit the list, or to accept the list. The system may notify the originator of the list that a user has edited the list. If the originator is a user of the system, the system may prompt the originator to indicate whether the originator wishes his or her list to be updated.  
      Returning to  FIG. 25   c,  the system may provide users with opportunities to associate documents with commodities. In response to a user indicating a desire to associate documents with a vacation property by, for example, selecting link  2575 , the system may provide an additional documents page. An illustrative additional, documents page  2700  is shown in  FIG. 27   a.  As shown in  FIG. 27   a,  the system may prompt the user to indicate whether the user wants to associate additional electronic or paper documents with a commodity. In response to a user indicating a desire to associate electronic documents, the system may prompt the user for a file name and path, or to browse for a file, as shown in  FIG. 27   b.  The user may upload the electronic documents to the system and the system may store them electronically. The system may also OCR the documents and search them for information regarding ownership rights and other information if desired.  
      In response to a user indicating a desire to associate paper documents with a commodity, the system may provide the user with a reference number and shipping instructions as shown in  FIG. 27   c.  Upon receiving the documents from the user, the system may scan in the documents, OCR them, and store them electronically. The system may also search the documents for information regarding ownership rights and other information if desired.  
      Returning to the illustrative portfolio page  1600  of  FIG. 16   a,  the system may provide users with opportunities to view and edit commodity information for commodities that are in the users&#39; portfolios. As shown in  FIG. 16   a,  for example, the system may provide a summary of a user&#39;s commodities. The listed commodities may be commodities acquired through the system, or commodities that were not acquired by the user using the system and for which information may have been entered as illustrated by the examples shown in  FIGS. 24   a - 24   c,    25   a - 25   c,    26 , and  27   a - 27   c.  Commodities may be organized using any suitable order, and summaries of any suitable commodities information may be shown. If desired, the information and commodities shown in portfolio pages may be user configurable.  
      The value of properties listed in portfolio page  1600  or in any other page may be displayed based on any suitable value. The system may display, for example, the amount paid for a commodity as its value. In another suitable approach, the system may calculate or obtain the market value or price of a commodity when the system provides its value (i.e., initially or when the user or the system refreshes the screen). In still another suitable approach, the system may periodically or continuously display and update the market value of a commodity. Fair market value may be calculated by the system using any suitable approach. The system may, for example, track sales of commodities similar in type, duration, ownership, source, or any other suitable criteria, and calculate a fair market value. In another approach, the system may obtain the market value of a commodity from a third party system. The provider of a commodity (e.g., a utility, computer service, etc.), for example, may provide the current price it is asking for similar commodities. A combination of display and value determination approaches may be used if desired.  
      In the example shown in  FIG. 16   a,  the user has five commodities. For the purposes of this example, assume that the first three listed commodities were acquired by the user using the system, and that the last two listed commodities were acquired by the user without the system. Also assume that commodity information has been entered for the last two listed commodities (e.g., as shown in  FIGS. 24   a - 24   c,    25   a - 25   c,    26 , and  27   a - 27   c ).  
      The system may also indicate to users when the users have received purchase or trade bids for their commodities. Portfolio page  1600  may include, for example, a bid indicator  1625  or  1627  for each commodity for which the system has matched a purchase request, and a trade indicator  1650  for each commodity for which the system has matched trade requests. Users may view purchase and trade requests by, for example, selecting indicators  1625 ,  1627 , and  1650 , respectively.  
      Users may indicate a desire to view additional information for a commodity by, for example, selecting its link. In response, the system may provide a commodities information page. The following five examples of commodities information pages are only illustrative. Commodities information pages may include any information suitable for the commodities for which commodity information is displayed. Any suitable graphical user interface element or combination of graphical user interface elements may be used to provide users with opportunities to access this information and perform other system features related to the commodities. The examples shown in  FIGS. 28   a - 28   d,    29   a - 29   e,    30   a - 30   e,    31   a - 31   c,  and  32  illustrate how the system may provide specialized pages based on the particular commodity a user selects, or the type of commodity selected.  
      An illustrative commodities information page  2800  that the system may display in response to a user selecting the link for commodity PFE is shown in  FIG. 28   a.  Commodities information page  2800  may display the type of commodity for which information is displayed. In this example, the type of commodity displayed is a stock. Other information related to stocks may be displayed, such as the full name of the stock, how many shares are owned, the price paid per-share, and the current market price. The current price may be determined and displayed using any suitable approach and frequency. Page  2800  may provide users with an opportunity to edit commodity information by, for example, selecting button  2807  and editing the information.  
      Page  2800  may also provide a user with an opportunity to access additional information and features related to the commodity. The user may, for example, access recent news about the stock, see its recent price history, sell all or some of the stock (discussed below), or trade the stock. If purchase or trade requests have been matched to the commodity, the system may provide the user with an opportunity to view the bids. Users may indicate a desire to, for example, view news about the stock by selecting link  2805 . In response, the system may provide a news page, such as illustrative news page  2850  of  FIG. 28   b.  Users may view articles by, for example, selecting their links. In this example, only one article for commodity PFE is available. Users may indicate a desire to, for example, view the recent price history of a stock by selecting link  2810  ( FIG. 28   a ). In response, the system may provide a price history page, such as illustrative price history page  2875  of  FIG. 28   c.  In this example, the price history is shown as a graph, but any suitable user interface element may be used.  
      Users may indicate a desire to view purchase or trade requests for the stock by, for example, selecting link  2815  ( FIG. 28   a ). Link  2815  may not be displayed when there are no pending requests. In response to the user selecting link  2815 , the system may display a request received page, such as illustrative request received page  2880  of  FIG. 28   d.  The system may also provide request received page  2880  when, for example, the user selects indicator  1625  from page  1600  of  FIG. 16   a.  In this example, the system has aggregated the user&#39;s shares to match a pending purchase request. The user may indicate a desire to accept or reject the pending request by, for example, selecting buttons  2885  or  2887 , respectively.  
      An illustrative commodities information page  2900  that the system may display in response to a user selecting the link for commodity Villas@fla from page  1600  of  FIG. 16   a  is shown in  FIG. 29   a.    
      Commodities information page  2900  may display the type of commodity for which information is displayed. In this example, the type of commodity displayed is vacation property. Other information related to vacation property may be displayed, such as the full name of the property, how it is owned or used by the user, the amount time for which it is owned or used, the time period during which it is owned or used, the amount paid, the current value, whether there are drag-along or tag-along rights, or any other suitable information. The current value may be determined and displayed using any suitable approach and frequency. Page  2900  may provide a user with an opportunity to edit commodity information by, for example, selecting button  2907  and editing the information.  
      Page  2900  may also provide a user with an opportunity to access additional information and features related to the commodity. The user may, for example, view co-owners, rent or buy additional time, sell the commodity, or trade the commodity. If purchase or trade requests have been received, the system may provide the user with an opportunity to view the requests. Users may indicate a desire to, for example, view co-owners by selecting link  2905 . In response, the system may provide a co-owners page, such as illustrative co-owners page  2950  of  FIG. 29   b.  Co-owners page  2950  may list the co-owners of the property for other weeks. In this example, the user has only a right to use the property. Co-owners may include other similar co-owners, or co-owners with other ownership rights (e.g., deeded weeks). Co-owners page  2950  may provide the user with an opportunity to view co-owners for other locations.  
      The system may provide the user with an opportunity to generate trade requests for other weeks by, for example, allowing the user to select a week and pressing button  2955 . In response, the system may provide a trade request page, such as illustrative page  2975  of  FIG. 29   c.  Page  2975  may also be provided in response to, for example, a user selecting link  2920  from page  2900  of  FIG. 29   a.  In this example, a user may define a trade request by, for example, selecting a particular week at the current location or selecting a week at some other location. In response to a user defining a trade request, the system may indicate to the user that the user will be notified whether the trade request is accepted as shown, for example, in  FIG. 29   d.    
      Returning to the illustrative commodities information page of  FIG. 29   a,  users may indicate a desire to view purchase or trade requests for the commodity by, for example, selecting link  2915 . If desired, link  2915  may not be displayed when there are no requests. In response to the user selecting link  2915 , the system may display a request received page, such as illustrative request received page  2990  of  FIG. 29   e.  The system may also provide illustrative request received page  2990  in response to a user selecting indicator  1650  from page  1600  of  FIG. 16   a.  In this example, the system has matched a trade request for two different weeks at the same location to the user&#39;s commodity. The user may indicate a desire to accept or reject the pending trade request by, for example, selecting buttons  2995  or  2997 , respectively. In response to the user accepting the bid, the system may initiate the trade.  
      An illustrative commodities information page  3000  that the system may display in response to a user selecting the link for commodity Dakota from page  1600  of  FIG. 16   a  is shown in  FIG. 30   a.  Commodities information page  3000  may display the type of commodity for which information is displayed. In this example, the type of commodity displayed is residential property. Other information related to residential property may be displayed, such as the full name of the property, its size, the amount paid, the current value, how it is owned or used by the user, whether there are drag-along or tag-along rights, or any other suitable information. The current value may be determined and displayed using any suitable approach and frequency. Page  3000  may provide users with an opportunity to edit commodity information by, for example, selecting button  3005  and editing the information.  
      Page  3000  may also provide a user with an opportunity to access additional information and features related to the commodity. The user may, for example, view co-owners, view additional documents, sell the property, or trade the property. If purchase or trade bids have been received, the system may provide the user with an opportunity to view the bids. Users may indicate a desire to view co-owners by, for example, selecting link  3010 . In response, the system may provide a co-owners page, such as illustrative co-owners page  3050  of  FIG. 30   b.  Users may select a link for a co-owner to view information regarding the co-owner. In this example, assume the user has selected the link for Joe Richetti. The system may display additional information for the co-owner, and provide the user with an opportunity to edit the information, as shown in  FIG. 30   c  (e.g., by pressing button  3017 ).  
      The system may provide a user with an opportunity to view additional documents related to a commodity. In this example, the user may indicate a desire to view additional documents by, for example, selecting link  3015  from page  3000  of  FIG. 30   a.  In response, the system may provide an additional documents page, such as illustrative documents page  3070  of  FIG. 30   d.  Documents page  3070  may list available documents and provide the user with an opportunity to view one or more documents. A user may indicate a desire to view a related document by, for example, selecting the document&#39;s link. In response, the system may provide the document for viewing by the user. In practice, the user&#39;s web browser may launch a viewer suitable for displaying the document (e.g., a Microsoft Word viewer, an Adobe Acrobat viewer, etc.). The system or the viewer may provide the user with an opportunity to print the related document.  
      Returning to the illustrative commodities information page  3000  of  FIG. 30   a,  a user may indicate a desire to view purchase or trade requests for the commodity by, for example, selecting link  3020 . If desired, link  3020  may not be displayed when there are no bids. In response to the user selecting link  3020 , the system may display a bid received page, such as illustrative bid received page  3070  of  FIG. 30   e.  The system may also provide illustrative bid received page  3070  in response to a user selecting indicator  1627  from page  1600  of  FIG. 16   a.  In this example, the system has matched a purchase request for Dakota. The user may indicate a desire to accept or reject the pending purchase request by, for example, selecting buttons  3095  or  3097 , respectively. The user may make a counter offer by, for example, pressing button  3099 . If desired, the power plant itself may be a commodity. A user could have a fractional ownership interest in either or both. In response to the user accepting the bid, the system may initiate the transfer of ownership from the user to the bidder or bidders.  
      An illustrative commodities information page  3100  that the system may display in response to a user selecting the link for commodity LIPA from page  1600  of  FIG. 16   a  is shown in  FIG. 31   a.  In this example, commodity information may have been obtained or generated when the user acquired the commodity using the system. Commodities information page  3100  may display the type of commodity for which information is displayed. In this example, the type of commodity displayed is utilities/electrical. That is, the commodity is the output of a power plant. Other information related to the utility may be displayed, such as the dates between which the user owns output from the source, the amount of output, the price paid, current value, whether there are drag-along or tag-along rights associated with a commodity, or any other suitable information. The current value may be determined and displayed using any suitable approach and frequency. Page  3100  may provide users with an opportunity to edit commodity information by, for example, selecting edit button  3105  and editing the information.  
      Page  3100  may also provide a user with an opportunity to access additional information and features related to the commodity. The user may, for example, view and edit the hourly consumption of the user within each day of output. If purchase or trade bids have been received, the system may provide the user with an opportunity to view the bids. Users may indicate a desire to view hourly consumption by, for example, selecting link  3110 . In response, the system may provide an hourly consumption page, such as illustrative hourly consumption page  2470  of  FIG. 24   c.    
      This example illustrates another feature of the system that may be provided within any commodity information page or other page. The system may provide users with an opportunity to split off their commodities. Users may desire to split off their commodities when, for example, the user has purchased an amount of the commodity that the user cannot exhaust. A split request may be issued to other users, other users of the same commodity, friends, or any other suitable set of users or non-users, and may indicate that the user wishes to sell or trade off some amount of an unused commodity. Users may indicate a desire to split off a commodity by, for example, selecting link  3120 . In response, the system may provide a split page that provides the user with an opportunity to define a split request. An illustrative split page  3150  is shown in  FIG. 31   b.  The system may provide the user with an opportunity to designate recipients of the request, the form of the request (i.e., sale or trade), and any other suitable information. In response to the user defining the split request, the system may indicate to the user that the user will be notified whether the split request has been accepted or countered as shown, for example, in page  3175  of  FIG. 31   c.  In response to a split request being accepted or a counter bid received and accepted, the system may initiate the transfer of ownership or trade of the split-off amount of the commodity.  
      An illustrative commodities information page  3200  that the system may display in response to a user selecting the link for commodity California Partners from page  1600  of  FIG. 16   a  is shown in  FIG. 32 . In this example, commodity information may have been obtained or generated when the user acquired the commodity using the system. Commodities information page  3200  may display the type of commodity for which information is displayed. In this example, the type of commodity displayed is vacation property with a deeded week form of ownership. Other information related to the vacation property may be displayed, such as the week of ownership, the network in which the property is managed, the price paid, the current value, whether there are drag-along or tag-along rights, or any other suitable information. The current value may be determined and displayed using any suitable approach and frequency. Page  3200  may provide the user with an opportunity to edit commodity information by, for example, selecting edit button  3205  and editing the information.  
      Page  3200  may also provide a user with an opportunity to access additional information and features related to the commodity. The user may, for example, view and edit co-owner information, or view or add additional related documents. In response to a user selecting link  3210 , for example, the system may provide a co-owner page, such as illustrative page  2600  of  FIG. 26 . In this example, there are no additional documents for the user to select. The user may add documents by, for example, selecting link  3215 . If purchase or trade requests have been received, the system may provide the user with an opportunity to view the requests. In this example, no requests have been received for commodity California Partners. The system may also provide users with an opportunity to split off some of the property by offering other users or non-users the opportunity to buy-in to the property (e.g., by selecting link  3220 ).  
      Returning to  FIG. 16   a,  the system may also provide users with opportunities to purchase commodities. Users may indicate a desire to purchase commodities by, for example, selecting link  88  from page  1600  or any page that includes link  88 . The system may also provide users with links to purchase commodities from within other pages. Illustrative page  2800  of  FIG. 28   a,  for example, illustrates how the system may provide users with an opportunity to purchase more of a type of commodity that the user already owns (e.g., by selecting link  2830 ). In response to the user indicating a desire to purchase commodities, the system may provide the user with an opportunity to select a commodity type as shown, for example, in page  3300  of  FIG. 33   a.  In response to a user selecting a commodity type, the system may provide a specialized purchase page. In an alternative approach, the system may provide a specialized purchase page, or other suitable purchase page, directly in response to a user indicating a desire to purchase a commodity (e.g., by selecting a link  2830  of page  2800 , or via some other link or suitable interface element).  
      For some types of commodities it may be desirable to provide additional pages to aid the user in selecting commodities the user wishes to purchase. It may be desirable, for example, to provide a source page of sources of a selected commodity type, such as illustrative source page  3350  shown in  FIG. 33   b.  Source pages may list available sources and the current market price of the commodities they provide, or any other suitable information. The current market price may be determined and displayed using any suitable approach and frequency. Users may indicate a desire to generate purchase requests for a single source by, for example, selecting that source&#39;s link. Users may indicate a desire to generate purchase requests for all it sources by, for example, selecting link  3355 . In still another suitable approach, the system may provide a suitable interface element to allow the user to select a subset of sources (e.g., check boxes, text fields, etc.)  
       FIG. 33   c  illustrates an illustrative purchase page  3375  that the system may display in response to, for example, the user selecting a source. In this example, the user has selected source West Coast. The system may prompt the user for a quantity and a bid. The user may indicate that the user has defined a bid by, for example, pressing button  3377 . The system may allow users to place market bids by, for example, not inputting a price. Users may also indicate a desire to purchase all available amounts of a commodity by, for example, leaving the quantity field blank. Both fields may be left blank by the user to indicate a desire to purchase all available amounts of a commodity at the current market price.  
      Purchase pages may provide users with opportunities to access other information or features related to a commodity. In this example, page  3375  provides users with an opportunity to view the average price history for the source. In response to a user selecting link  3399 , the system may provide a price history page, such as illustrative page  3390  of  FIG. 33   d.  The system may also provide users with opportunities to participate in auctions for commodities. Users may indicate a desire to participate in pending auctions by, for example, selecting link  3391  from  FIG. 33   c.  In response, the system may provide an auction page, such as illustrative auction page  3395  of  FIG. 33   e.    
      Auction pages may display current auctions for commodities of the selected source, or all sources. Illustrative page  3395 , for example, displays two current auctions. The user may participate in an auction and make a bid by, for example, selecting a link for an auction. In response the system may provide a page into which the user may input a bid. The user may initiate an auction by, for example, selecting button  3392  and placing a bid for a quantity of a commodity not shown, or for a commodity from a different source. The system may aggregate new bids to match a current bid if desired.  
       FIGS. 34   a - 34   d  illustrate another example of specialized pages for providing users with opportunities to purchase real property and, in particular, vacation property. As shown in  FIG. 34   a,  the user has selected commodity type real property/vacation within page  3400 . In response, the system may provide additional pages to aid the user in defining a purchase request. As shown in page  3405  of  FIG. 34   b,  for example, the system may provide the user with an opportunity to indicate a country, region, or continent. In response, the system may, for example, provide a graphical representation of the selected country, region, or continent, as shown in page  3410  of  FIG. 34   c.  The user may indicate a more specific region from which the user may purchase property by, for example, selecting a region. Alternatively, the user may indicate a desire to define a bid for all or a subset of regions by, for example, selecting link  3415 .  
      In response to a user selecting a region from page  3410 , the system may provide a purchase request page. The system may also provide purchase request pages in response to a user indicating a desire to purchase commodities in other ways (e.g., by selecting link  2830  from  FIG. 28   a ). Purchase request pages may provide the user with opportunities to view current asks, participate in or initiate auctions, view specific properties that the user may place a bid for, define a bid to include a class of commodities, or to generate a purchase request using any other suitable approach.  FIG. 34   d  shows illustrative purchase request page  3420 .  
      Users may indicate a desire to view current asks by, for example, selecting link  3423 . In response, the system may display an asks page. Asks pages may list current sales requests for all commodities, for the subset of all commodities in which the user has indicated an interest (in this example for all vacation property in zone  9  in the United States), or for any other suitable subset of commodities.  FIG. 35   a  shows an illustrative asks page  3500  for all vacation properties in zone  9  in the United States. In this example, there are only two pending asks, or sales requests. A user may indicate a desire to view information about a commodity by selecting its link. In response, the system may provide an ask/bid page, such as illustrative ask/bid page  3525  shown in  FIG. 35   b.  In this example, the user has selected the ask for a commodity provided by Resorts Plus. Ask/bid pages may provide the user with information about the commodity and its current ask, and may provide the user with an opportunity to meet the ask or provide a counter-offer. A user may meet a bid by, for example, pressing button  3527 . In response, the system may initiate the transfer of ownership of the commodity. In response to a user indicating a desire to enter a in counter-offer (e.g., by pressing button  3529 ), the system may provide a counter page, such as illustrative counter page  3550  shown in  FIG. 35   c.  In response to the user entering a counter offer, the system may indicate to the user that the user will be notified of whether the counter is accepted, as shown in page  3575  of  FIG. 35   d.    
      The system may also provide users with opportunities to view pictures of offered commodities. Users may indicate a desire to view a picture or video of an offered property by, for example, selecting link  3531  of page  3525  ( FIG. 35   b ). In response, the system may provide a suitable graphic or video image or file for display.  
      Users may indicate a desire to participate in auctions for commodities by, for example, selecting link  3425  of page  3420  ( FIG. 34   d ). In response, the system may provide an auctions page. Auctions pages may display the current pending auctions for all commodities, for the subset of all commodities in which the user has indicated an interest (in this example all vacation properties in zone  9  in the United States), or for any other suitable subset of commodities. In the illustrative auctions page  3600  of  FIG. 36   a,  the user has selected to view auctions for vacation property in zone  9  of the United States. In this example, there is only one pending auction. The user may indicate a desire to view information regarding the auctioned commodity by, for example, selecting the associated link. In response the system may provide an auction information page, such as illustrative information page  3625  of  FIG. 36   b.    
      Auction information page  3625  may list information for an auctioned vacation property, such as the name, location, available week, opening bid or ask, and current bid. The system may update the current bid each time a bid is placed, allowing the user to wait and see if additional bids are placed before bidding. The user may indicate a desire to enter a bid by, for example, pressing button  3650 . In response, the system may provide a bid page, such as illustrative bid page  3635  of  FIG. 36   c.  Bid pages, such as page  3635 , may allow users to enter a bid. Bid pages may also provide users with an opportunity to split the bid with someone else, a further illustrative use of the split feature of the present invention. In response to the user selecting link  3640 , for example, the system may provide a split page.  
      An illustrative split page is shown in  FIG. 36   d  (a first illustrative split page for splitting off ownership was shown previously in  FIG. 31   b ). Unlike split  3150  page of  FIG. 31   b,  page  3645  may provide the user with an opportunity to choose one or more specific friends or other users or non-users that the user may wish or need to share the current opportunity with. In response to the user generating a split request by, for example, filling in page  3645 , the system may provide a message to the friends (or other users or non-users) by, for example, system messages, e-mail, or regular mail, prompting them for a response. Unlike page  3150  of  FIG. 31   b,  page  3645  provides the user with an opportunity to define a message. If desired a combination of the approaches shown in  FIGS. 31   b  and  36   d  may be used. For example, page  3150  of  FIG. 31   b  may be modified to provide a user with an opportunity to define a message. Any other suitable approach may also be used. The user may place a bid on behalf of all parties participating in a split by, for example, selecting radio button  3647  of page  3635  of  FIG. 36   c  and entering the participants&#39; names in scrollable text-box  3650 .  
      The system may allow a user to define purchase requests by, for example, browsing commodities within the system, selecting a commodity for which the user wishes to define a purchase request, and defining a purchase request. Users may indicate a desire to browse commodities by, for example, selecting link  3427  of  FIG. 34   d.  In response, the system may provide a browse page in which commodities are listed and provided to the user for selection. An illustrative browse page  3700  is shown in  FIG. 37   a.  In this example, the user has indicated a desire to browse vacation properties in zone  9  of the United States. Browse page  3700  lists properties and their current sale or auction status. As illustrated in  FIG. 37   a,  there are two commodities that are currently offered for sale, one property for which an auction is pending, and additional properties that are currently not offered for sale or auction. The user may indicate a desire to view additional information for a commodity by, for example, selecting its link. In response, the system may provide a commodities information page, such as illustrative commodities information page  3725  of  FIG. 37   b.    
      Commodities information page  3725  may include information about the commodity, as well as provide the user with opportunities to view pictures or videos of the commodity, make a bid for the commodity, or generate a split request. A user may indicate a desire to view pictures or videos for a commodity by, for example, selecting link  3727 . In response, the system may provide a suitable graphic or video image or file for display.  
      The user may indicate a desire to make a bid for a commodity by, for example, selecting link  3729 . In response, the system may provide the user with an opportunity to define a bid for the selected commodity. An illustrative page for providing a user with an opportunity to define a bid for a selected commodity is shown on page  3733  of  FIG. 37   c.  As shown, the user may indicate whether the user wishes to buy or rent the property, the rental term (if applicable), and the bid price.  
      The user may indicate a desire to generate a split request by, for example, selecting link  3731  of  FIG. 37   b.  In response, the system may provide the user with an opportunity to define a split as described, for example, in connection with  FIG. 31   b  or  36   d.    
      The system may provide a user with an opportunity to define purchase requests using, for example, natural language or boolean expressions. A user may indicate a desire to define a bid by, for example, selecting link  3429  of  FIG. 34   d.  In response, the system may provide a define purchase request page. A define purchase request page may provide the user with an opportunity to define a request for specific unique or fungible commodity, or for a class of commodities, depending on how the user formulates the user&#39;s expression. An illustrative define purchase request page  3800  is shown in  FIG. 38   a.  As shown in  FIG. 38   a,  the system may provide the user with an opportunity to indicate the type of expression the user will define, and to define the expression.  FIG. 38   a  illustrates the use of radio buttons and a text-box to provide these opportunities, but any suitable combination of user interface elements may be used.  FIG. 38   a  also illustrates how the system may provide a user with an opportunity to indicate that the user wishes to receive close matches. The user may indicate that the user is finished defining an expression by, for example, pressing button  3810 .  
      In response to the user defining an expression, the system may search for commodities, in this example vacation properties, that match the expression. The system may present the found commodities in a matched commodities page, such as illustrative matched commodities page  3825  of  FIG. 38   b.  In the example of  FIG. 38   b,  only one property was found that matched the expression. The user may indicate a desire to access additional information about the commodity by, for example, selecting a link associated with the commodity. In response, the system may provide a commodities information page, such as illustrative commodities information page  3725  of  FIG. 37   b.  The system may provide the user with an opportunity to make a bid or split as shown in  FIG. 37   b  or, because this commodity is for sale, the system may provide the user with an opportunity to purchase the property at the asking price.  
      Returning to  FIG. 16   a,  the system may provide users with opportunities to sell commodities. A user may indicate a desire to sell a commodity or commodities by, for example, selecting link  90  from page  1600  or any other page that contains link  90 , selecting a link from a commodities information screen (e.g., link  2825  of  FIG. 28   a,  link  2925  of  FIG. 29   a,  link  3030  of  FIG. 30   a,  link  3130  of  FIG. 31   a,  and link  3230  of  FIG. 32   a ), or using any other suitable approach. In response to a user selecting link  90 , for example, the system may prompt a user to indicate the commodity that the user wishes to sell, as shown in page  3900  of  FIG. 39 . In response to the user selecting a commodity, the system may provide a sell commodity page.  
      An illustrative sell commodity page  4000  that the system may provide in response to the user indicating a desire to sell commodity PFE is shown in  FIG. 40   a.  Sell commodity page  4000  may display, for example, the type of commodity (in this example a stock), its name, the total amount of shares owned, the price originally paid for each share, the current price, whether there are drag-along or tag-along rights, or any other suitable information. The current price may be determined and displayed using any suitable approach and frequency. Sell commodity page  4000  may also provide the user with an opportunity to specify a price for the commodity. The user may, for example, specify that the shares be sold at the current market price or at some other asking price. The user may also specify the number of shares (i.e., all or a portion of the user&#39;s total holdings of the commodity) the user wishes to sell. The user may also specify a purchasing user or purchasing users to whom the selling user wishes to sell the commodity. When the user finishes defining the sales request (e.g., by pressing button  4008 ), the system may generate the sales request and attempt to match it with pending purchase requests if a purchasing user or users are not specified. In this example, the commodity is not co-owned. If the commodity were co-owned, the system may notify the other co-owners of the pending sales request. If there were drag-along rights, the system may provide the co-owners with an opportunity to purchase the commodity before other non-co-owners.  
      The user may indicate a desire to auction the commodity, or a portion of the commodity, by, for example, selecting link  4010 . In response, the system may provide an auction page. An illustrative auction page  4025  is shown in  FIG. 40   b.  In this example, a Dutch auction is used. The seller offers all of the shares at the market price, and keeps lowering the price until all of the shares are sold. Any suitable open or closed auction approach may be used to sell a commodity. In this example, the commodity is not co-owned. If the commodity were co-owned, the system may notify the other co-owners of the pending auction request. If there were drag-along rights, the system may provide the co-owners with a private auction to offer them the opportunity to purchase the commodity.  
      An illustrative sell commodity page  4100  that the system may provide in response to the user indicating a desire to sell commodity Villas@fla is shown in  FIG. 41   a.  Sell commodity page  4100  may display, for example, the type of commodity (in this example vacation property), its name, the type of ownership, the term of ownership (if applicable), the time period during which the commodity is owned, the amount paid, the current value, whether there are drag-along or tag-along rights, or any other suitable information. The current value may be determined and displayed using any suitable approach and frequency. Sell commodity page  4100  may also provide the user with an opportunity to specify a price for the commodity. The user may, for example, specify that the property be sold at the current market price or at some other asking price. The user may also specify a purchasing user or purchasing users to whom the selling user wishes to sell the commodity. When the user finishes defining the sales request (e.g., by pressing button  4105 ), the system may generate the sales request and attempt to match it with pending purchase requests if a purchasing user is not specified. In this example, the seller has only a right to use. The system may notify the other co-owners, the manager of the property, or the real owner of the property, of the pending sales request, and provide them an opportunity to purchase the commodity before other non-co-owners.  
      The user may indicate a desire to auction the commodity, or a portion of the commodity, by, for example, selecting link  4110 . In response, the system may provide an auction page. An illustrative auction page  4125  is shown in  FIG. 41   b.  In this example, an English auction is provided. The seller has offered the property at the current market price, and bidders keep bidding higher until the highest bid is reached, until the user accepts an offer, or until the user stops the auction, at a time specified by the user, or when no bids are received for a user-specified or system-specified period of time. Any suitable open or closed auction approach may be used to sell a commodity. In this example, the seller has only a right to use. The system may notify the other co-owners, the manager of the property, or the real owner of the property, of the pending auction request, and provide them an opportunity to purchase the commodity before other non-co-owners.  
      An illustrative sell commodity page  4200  that the system may provide in response to the user indicating a desire to sell commodity Dakota is shown in  FIG. 42   a.  Sell commodity page  4200  may display, for example, the type of commodity (in this example residential property), its name, size, the amount paid, the current value, the type of ownership, whether there are drag-along or tag-along rights, or any other suitable information. The current price may be determined and displayed using any suitable approach and frequency. Sell commodity page  4200  may also indicate to the user whether there is a pending request for the commodity. The user may review the request by, for example, selecting link  4210 . In response the system may provide a request information page, such as illustrative request information page  4575  of  FIG. 45   c.    
      Sell commodity pages such as sell commodity page  4200  may also provide the user with an opportunity to specify a price for a commodity. The user may, for example, specify that the property be sold at the current market price or at some other asking price. The user may also specify a purchasing user or purchasing users to whom the selling user wishes to sell the commodity. When the user finishes defining the sales request (e.g., by pressing button  4205 ), the system may generate the sales request and attempt to match it with pending purchase requests if a purchasing user or users are not specified. In this example, the seller has only a right to use. The system may notify the other co-owners, the manager of the property, or the real owner of the property, of the pending sales request, and provide them an opportunity to purchase the commodity before other non-co-owners. By providing the user with an opportunity to sell the user&#39;s right to use, the system effectively puts the user into direct ownership of the property. The system may also put the user or a purchaser into direct ownership by, for example, providing for the sale of the property as a deeded-week property.  
      The user may indicate a desire to auction the commodity, or a portion of the commodity, by, for example, selecting link  4212 . In response, the system may provide an auction page. An illustrative auction page  4225  is shown in  FIG. 42   b.  In this example, an English auction is used. The seller has offered the property at the current market price, and bidders keep bidding higher until the highest bid is reached, until the user accepts an offer, or until the user stops the auction, at a time specified by the user, or when no bids are received for a user-specified or system-specified period of time. Any suitable open or closed auction approach may be used to sell a commodity. In this example, the seller has only a right to use. The system may notify the other co-owners, the manager of the property, or the real owner of the property, of the pending auction request, and may provide them an opportunity to purchase the commodity before other non-co-owners.  
      An illustrative sell commodity page  4300  that the system may provide in response to the user indicating a desire to sell commodity LIPA is shown in  FIG. 43   a.  Sell commodity page  4300  may display, for example, the type of commodity (in this example utilities/electrical), its name, the amount paid, the output purchased, the current value, the type of ownership, whether there are drag-along or tag-along rights, or any other suitable information. The current price may be determined and displayed using any suitable approach and frequency. Sell commodity page  4300  may also provide the user with an opportunity to specify a price for the commodity. The user may, for example, specify that the commodity be sold at the current market price or at some other asking price. The user may also specify a purchasing user or purchasing users to whom the selling user wishes to sell the commodity. When the user finishes defining the sales request (e.g., by pressing button  4305 ), the system may generate the sales request and attempt to match it with pending purchase requests if a purchasing user or users are not specified. In this example, the commodity is not co-owned.  
      The user may indicate a desire to auction the commodity, or a portion of the commodity, by, for example, selecting link  4310 . In response, the system may provide an auction page. An illustrative auction page  4325  is shown in  FIG. 43   b.  The seller has offered the commodity at the price paid, and bidders keep bidding higher until the highest bid is reached, until the user accepts an offer, or until the user stops the auction, at a time specified by the user, or when no bids are received for a user-specified or system-specified period of time. Any suitable open or closed auction approach may be used to sell a commodity. In this example, the commodity is not co-owned.  
      An illustrative sell commodity page  4400  that the system may provide in response to the user indicating a desire to sell commodity California Partners is shown in  FIG. 44   a.  Sell commodity page  4400  may display, for example, the type of commodity (in this example vacation property), its name, the amount paid, the current value, the type of ownership (in this example deeded week), whether there are drag-along or tag-along rights, or any other suitable information. The current price may be determined and displayed using any suitable approach and frequency. Sell commodity page  4400  may also provide the user with an opportunity to specify a price for the commodity. The user may, for example, specify that the property be sold at the current market price or at some other asking price. The user may also specify a purchasing user or purchasing users to whom the selling user wishes to sell the commodity. When the user finishes defining the sales request (e.g., by pressing button  4405 ), the system may generate the sales request and attempt to match it with pending purchase requests if a purchasing user is not specified. In this example, the property is owned by deeded-week. Thus, there may be co-owners of the user&#39;s property for other weeks. In this example, the user has drag-along rights. Accordingly, the user may drag the co-owners of the property along in the sale. The system may notify the co-owners and provide them with an opportunity to purchase the property.  
      The user may indicate a desire to auction the commodity, or a portion of the commodity, by, for example, selecting link  4410 . In response, the system may provide an auction page. An illustrative auction page  4425  is shown in  FIG. 44   b.  In this example, an English auction is provided. The seller has offered the commodity at the price paid, and bidders keep bidding higher until the highest bid is reached, until the user accepts an offer or until the user stops the auction, at a time specified by the user, or when no bids are received for a user-specified or system-specified period of time. Any suitable open or closed auction approach may be used to sell a commodity. In this example, the commodity is co-owned with drag-along rights. The system may notify the co-owners and provide them with an opportunity to purchase the property at the highest bid.  
      A user may indicate a desire to define a sales request by, for example, selecting link  3910  of  FIG. 39 . In response, the system may provide a define sales request page. A define sales request page may provide the user with an opportunity to define a request for a specific unique or fungible commodity, or for a class of commodities, depending on how the user formulates the user&#39;s expression. An illustrative define sales request page  4500  is shown in  FIG. 45   a.  As shown in  FIG. 45   a,  the system may provide the user with an opportunity to indicate the type of expression the user will define, and to define the expression.  FIG. 45   a  illustrates the use of radio buttons and a text-box to provide these opportunities, but any suitable combination of user interface elements may be used. The system may, for example, provide the user with a list of key words (e.g., type, price, etc.) to choose from when defining a boolean expression. The user may indicate that the user is finished defining an expression by, for example, pressing button  4510 . In this example, the user&#39;s only commodity that satisfies the expression is Dakota.  
      In response to the user defining an expression, the system may search for purchase requests that match the expression. The system may present the matched requests in a matched requests page, such as illustrative matched requests page  4550  of  FIG. 45   b.  In the example of  FIG. 45   b,  only one request was found that matched the expression exactly. The other requests matched in type but not in price. The user may indicate a desire to access additional information about a request by, for example, selecting a link associated with the request. In response, the system may provide a request information page, such as illustrative request information page  4575  of  FIG. 45   c.  In this example, the purchasing user has defined his request as a natural language expression for a class of commodities. Request information page  4575  may provide the user with an opportunity to accept the request, reject the request, or provide a counter-offer.  
      Returning to  FIG. 16   a,  the system may also provide users with opportunities to trade commodities. In response to a user indicating a desire to trade commodities by, for example, selecting link  92  from page  16   a  or any page that includes link  92 , the system may provide a commodity selection page, such as illustrative commodity selection page  4600  of  FIG. 46 . The user may indicate a desire to trade a particular commodity by, for example, selecting a link associated with the commodity. Users may also indicate a desire to trade a commodity by, for example, selecting link  2820  of  FIG. 28   a,  link  2920  of  FIG. 29   a,  link  3025  of  FIG. 30   a,  link  3135  of  FIG. 31   a,  or link  3235  of  FIG. 32 .  
      In response to a user indicating a desire to trade a particular commodity, the system may provide a trade request page. Page  4700  of  FIG. 47   a  illustrates a trade request page that the system may provide when, for example, the user indicates a desire to trade commodity PFE. The system may provide the user with an opportunity to select a type of commodity for which the user wishes to trade commodity PFE. In this example the user has selected commodities of type real property/vacation. The system may also provide the user with an opportunity to indicate a particular property, or to define a class of properties, either of which may be accomplished by, for example, defining an expression. In an alternative approach, the system may provide the user with an opportunity to indicate a particular commodity or class of commodities without first selecting a type. Once the user has indicated a commodity type, particular property, or a class of properties, the system may attempt to match the trade request. In this example, the system has found no matches. The system may indicate to the user that no matches were found and that the system will notify the user when a match is found as shown, for example, in page  4710  of  FIG. 47   b.    
       FIG. 47   c  illustrates a trade request page  4720  that the system may provide when, for example, the user indicates a desire to trade commodity Villas@fla. The system may provide the user with an opportunity to select a type of commodity for which the user wishes to trade commodity Villas@fla. In this example the user has selected commodities of type real property/vacation. The system may provide the user with an opportunity to indicate a particular property, or to define a class of properties, either of which may be accomplished by, for example, defining an expression. In an alternative approach, the system may provide the user with an opportunity to indicate a particular commodity or class of commodities without first selecting a type. Once the user has indicated a particular property, or a class of properties, the system may attempt to match the trade request. In this example, the system has found a match as shown in page  4730  of  FIG. 47   d.  The system may provide the user with an opportunity to trade commodities by, for example, pressing button  4725 . The system may respond by initiating the trade. When either of the traded commodities are co-owned, the system may notify the co-owners of the trade. When either commodity is co-owned subject to drag-along or tag-along rights, the system may provide the co-owners with opportunities to participate in the trade. Users may obtain additional information by, for example, selecting a link associated with the matched commodity.  
       FIG. 47   e  shows an illustrative trade request page  4740  that the system may provide when, for example, the user indicates a desire to trade commodity Dakota. The system may provide the user with an opportunity to select a type of commodity for which the user wishes to trade commodity Dakota. In an alternative approach, the system may provide the user with an opportunity to indicate a particular commodity or class of commodities without first selecting a type. In this example the user has selected commodities of type real property/residential. The system may provide the user with an opportunity to indicate a particular property, or to define a class of properties, either of which may be performed by defining an expression. Once the user has indicated a particular property, or a class of properties, the system may attempt to match the trade request. In this example, the system has found a match as shown in page  4750  of  FIG. 47   f.  The system may provide the user with an opportunity to trade commodities by, for example, pressing button  4735 . The system may respond by initiating the trade. When either of the traded commodities are co-owned, the system may notify the co-owners of the trade. When either commodity is co-owned subject to drag-along rights, the system may provide the co-owners with opportunities to participate in the trade. Users may obtain additional information by, for example, selecting a link associated with the matched commodity.  
       FIG. 47   g  illustrates a trade request page  4760  that the system may provide when, for example, the user indicates a desire to trade commodity LIPA. The system may provide the user with an opportunity to select a type of commodity for which the user wishes to trade. In this example the user has selected commodities of type utilities/oil. The system may provide the user with an opportunity to indicate a particular commodity, or to define a class of commodities, within the selected type if desired. In an alternative approach, the system may provide the user with an opportunity to indicate a particular commodity, or to define a class of commodities, without first selecting a type. Any suitable approach may be used.  
      Once the user has indicated a particular property, or a class of properties, the system may attempt to match the trade request. In this example, the system has found a match as shown on page  4770  of  FIG. 47   h.  The system may provide the user with an opportunity to trade commodities by, for example, pressing button  4745 . The system may respond by initiating the trade. When either of the traded commodities are co-owned, the system may notify the co-owners of the trade. When either commodity is co-owned subject to drag-along rights, the system may provide the co-owners with opportunities to participate in the trade. Neither of the commodities in this example are co-owned.  
       FIG. 47   i  illustrates a trade request page  4780  that the system may provide when, for example, the user indicates a desire to trade commodity California Partners. The system may provide the user with an opportunity to select a type of commodity for which the user wishes to trade commodity California Partners. In this example the user has selected commodities of type real property/vacation. The system may provide the user with an opportunity to indicate a particular commodity, or to define a class of commodities, within the selected type if desired. In an alternative approach, the system may provide the user with an opportunity to indicate a particular commodity, or to define a class of commodities, without selecting a type. Any suitable approach may be used.  
      Once the user has indicated a particular property, or a class of properties, the system may attempt to match the trade request. In this example, the system has found a match as shown on page  4790  of  FIG. 47   j.  The system may provide the user with an opportunity to trade commodities by, for example, pressing button  4755 . The system may respond by initiating the trade. When either of the traded commodities are co-owned, the system may notify the co-owners of the trade. When either commodity is co-owned subject to drag-along rights, the system may provide the co-owners with an opportunity to participate in the trade. Users may obtain additional information by, for example, selecting a link associated with the matched commodity.  
      The system may also provide a user with an opportunity to define trade requests using, for example, natural language or boolean expressions. In the illustrative define request page  4795  of  FIG. 47   k,  for example, the user has indicated that the user wishes to define a trade request as a natural language expression. In response to the user indicating that the user has finished the expression (e.g., by pressing button  4780 ), the system may attempt to find trade requests of other users that match the expression. When matches are found the system may, for example, provide the user with an opportunity to select a request to trade with or to reject all requests.  
      The system may also provide users with an opportunity to perform maintenance functions, such as perform maintenance schedule changes, perform maintenance fee changes, change conditions of membership in an ownership network, indicate changes in IBM liquidity, or any other suitable function. The system may, for example, provide co-owners with opportunities to schedule their uses of a commodity, or to move commodities across networks of commodities. The system may provide users with opportunities to place orders for renting other owners&#39; commodities or other co-owners&#39; shares in commodities (e.g., temporal use rights). Any other suitable maintenance action may be provided. Users may indicate a desire to perform maintenance functions by, for example, selecting link  94  from within any page that provides the link. In response, the system may provide a maintenance page, such as illustrative maintenance page  4800  of  FIG. 48   a.  A user may indicate a desire to access a maintenance function by, for example, selecting a link associated with the function.  FIG. 48   b  shows an illustrative page  4825  that the system may provide in response to a user selecting links  4805 ,  4810 ,  4815 , or  4820 . Page  4825  provides the user with an opportunity to indicate the property for which the user wishes to change additional commodity information. The chosen user interface element in, page  4825  is text box  4835 . The user may enter one or more words that the system may search on to find a particular commodity. After finding the commodity, the system may provide the user with an opportunity to change the associated information.  
      An illustrative page  4830  that the system may provide in response to a user selecting link  4805  and identifying a commodity is shown in  FIG. 48   c.  The user may indicate a desire to change additional commodity information by, for example, selecting a link associated with a type of information. In response, the system may provide a page or pages with interface elements suitable for allowing the user to change the indicated information. In response to a user changing additional commodity information, the system may notify the owner (if the user is not the owner of the commodity) or co-owners of the property of the change in information.  
       FIG. 48   d  shows an illustrative page  4840  that the system may provide in response to a user indicating a desire to move commodities across networks by, for example, selecting link  4810  ( FIG. 48   a ) and identifying a commodity. In this example, the user has selected commodity California Partners. The system may provide the user with an opportunity to identify a destination network. In response to the user identifying a network, the system may transfer the commodity to the destination network.  
       FIG. 48   e  shows an illustrative page  4850  that the system may provide in response to the user indicating a desire to schedule uses of a commodity by, for example, selecting link  4815  ( FIG. 48   a ) and identifying a commodity. Scheduling uses of a commodity may be useful for any type of commodity that has time-based ownership or use rights (e.g., deeded-weeks, right to use, rentals, computer processing, utility output, etc.). The system may allow the user to select co-owners and change their weeks, or to select weeks and edit co-owners. Any other suitable approach may be used. The user may indicate that the user is finished by, for example, pressing button  4835 . In response, the system may update the commodity information of the commodity. The system may update the user information for the co-owners if they are users. The system may also notify the co-owners of the change in the use schedule.  
       FIG. 48   f  shows an illustrative page  4860  that the system may provide in response to a user indicating a desire to place rental orders by, for example, selecting link  4820  ( FIG. 48   a ) and identifying a commodity. Rental orders may be placed, for example, for any co-owned or wholly owned commodity that a user wishes to use for a period of time but not purchase. The system may not need, with some types of commodities, to initiate a transfer of ownership as a result of a rental request. Users may, for example, select a week. The system may display the asking price for that week of a commodity. If no asking price is set, the system may allow the user to enter a bid. When an asking price is set, the user may indicate that the user accepts the price by, for example, pressing button  4871 . The user may enter a counter-offer by, for example, pressing button  4873 . The system may notify the owner of the property of the counter-offer and provide the owner with an opportunity to, for example, accept or reject the offer.  
      The system may also provide a user with an opportunity to read messages provided to the user by the system. The user may indicate a desire to access messages by, for example, selecting link  96  from any page that includes the link. In response, the system may provide a system message page that shows the user the messages waiting for the user.  FIG. 49  shows an illustrative system message page  4900 . In the example of  FIG. 49 , the user has two system messages. The first message is a split request sent to the user from another user. The second message is a message indicating that a request to change networks for a commodity was approved by other co-owners of a commodity. Users may select a link associated with a message to view the entire message and, if desired, respond to the message.  
      Thus, an enhanced promotional channel is provided. One skilled in the art will appreciate that the present invention can be practiced by other than the described embodiments, which are presented for purposes of illustration and not of limitation, and the present invention is limited only by the claims which follow.