Technologies relating to the transmission of voice, data, video and other multimedia have been converging, enabling various networks to interact and thereby provide a plethora of multimedia offerings.  For example, the Video Share™ service of AT&T is offered over mobile networks and may be enabled by IMS (IP Multimedia System).  Through the Video Share™ service, users that are engaged in a mobile voice call can initiate a packet-implemented, video streaming session.  In another example of converging technologies, dual mode handsets permit a customer's mobile terminal to support, for example, access to both cellular networks and local area networks. 
Databases are used to assist in the provision of various services.  For example, Jini, developed at Sun Microsystems, is a distributed computing architecture over which a service may operate.  As part of the Jini architecture, there may be a database lookup service which may provide, to a client that wants to use the service, information on how to connect directly to the service. 
In other technologies, information relating to users enables those users to communicate with each other more effectively.  U.S. Pat.  No.  7,310,676 discloses “a business or social networking method [that] is operative in a server.  The method enables mobile device users to meet one another, on a permission basis.  The determination of whether a given pair of mobile device users are introduced depends on whether the server determines they are in intellectual or ‘cognitive’ proximity, which is typically a function of one or more factors, such as: each user's reciprocal networking objective, the nature of the industry in which the user works, the user's level within the management hierarchy of his or her company, any specialty function the individual may possess, and so on.  Individuals who are matched in one or more of such attributes to a given degree or threshold are said to be in intellectual proximity.  According to the invention, when given mobile devices users are within physical proximity of one another during an overlapping time window, the server determines whether the users are also within a given intellectual proximity.” 
U.S. Pat.  No.  7,251,696 discloses a “system and method for identifying communication channels and appropriate timing of communications that facilitate enhancing or maximizing the utility of a communication between communicating parties, based on the participants' preferences and capabilities. . . .  The system and method implement policies for facilitating optimal communications between communicating parties based on deterministic and/or uncertain preferences, capabilities and context, both present and predicted, where a decision to employ an initially selected channel and timing of communication may be overridden by contactor or contractee based on user-configurable triggers.  The system and method further provide for mixed/multi-initiative overriding of the identified optimal communication channel and indicated best time for a communication.  The methods can be implemented on a wide scale communication system or within a single portable device.” 
U.S. Pat.  No.  5,086,394 discloses “An introduction system for participating users [that] includes for each user a personal device that is subject to activation by remote paging.  Each user also has a memory device that contains personal data defining the user by personal characteristics such as traits and interests.  A local control unit receives the respective personal data from a plurality of user memory devices and using computer means compares the personal data of each user with the personal data of other users who have within the same time frame entered their personal data into the local control unit via their respective memory devices.  Pairs who are matched to predetermined standards by the computer comparison are automatically paged via their personal devices and an introduction is facilitated.” 
U.S. Patent Application Publication 20080126484 discloses “[a] method and system for determining and sharing a user's web presence. . . .  According to one embodiment, a computer implemented method comprises providing web presence information associated with a first user from a first computer having a first software module.  The web presence information is received at a second computer.  The web presence information is used to dynamically inform a second user communicating with the second computer of a website that the first user is viewing.” 
U.S. Pat.  No.  7,408,920 involves “[a]n Active User Registry system [that] includes a database which is integrated with the POTS network and a packet network to exploit the outstanding strengths of both of its constituents.  The Active User Registry database is a dynamic data structure of all the ways in which one or more users can be reached via some type of communication network.  A key feature of the Active User Registry is the ability to broker between a subscriber's request for communications contact information corresponding to a user and the user's preferences of being reached by various communications alternatives.” 
U.S. Pat.  No.  5,901,359 involves [a] single-number service for providing integrated wireless and wireline communication networks for forwarding a call incoming to a subscriber's designated single telephone number to a routing destination number based on the subscriber's current location is provided.  The single-number service includes storing subscriber mobile registration status in a wireline location register (WLR) of the wireline communication network.  The subscriber mobile registration status is retrieved upon receiving the call incoming to the subscriber's designated single telephone number.  The call is routed to a wireline destination stored in the WLR in response to the subscriber mobile registration status indicating that the subscriber is wireline registered.  A subscriber location request is sent from the WLR to the Home Location Register (HLR) of the wireless network in response to the subscriber mobile registration status indicating that the subscriber is wireless registered.  A routing request is sent from the HLR to the MSC where the subscriber is registered in response to receiving the subscriber current location request.  A wireless routing destination number (TLDN) is communicated from the MSC to the WLR.  The call incoming to the subscriber's directory number is routed by the WLR to the wireless routing destination number (TLDN).