<PAGE>

                                                                    EXHIBIT 10.1

                         REGISTRATION RIGHTS AGREEMENT
                         -----------------------------

          This REGISTRATION RIGHTS AGREEMENT (this "Agreement") is made and
entered into as of this 29th day of December, 2000, by and among ALLIN
CORPORATION, a Delaware corporation (the "Company") and those persons whose
names appear on the signature page hereof (collectively, the "Subscribers").

                             W I T N E S S E T H:
                             - - - - - - - - - -

          WHEREAS, the Subscribers have agreed to purchase from the Company
shares of Series G Redeemable Preferred Stock, par value $.01 per share, of the
Company (the "Series G Preferred Stock") and related warrants (the "Warrants")
to purchase shares of common stock, par value $.01 per share, of the Company
(the "Common Stock"); and

          WHEREAS, the Company will not issue the Series G Preferred Stock or
the Warrants until such time that the holders of the outstanding Common Stock
approve such issuances; and

          WHEREAS, the Series G Preferred Stock and the Warrants, if issued,
will be issued to the Subscribers without registration under the Securities Act
of 1933, as amended, and applicable state securities laws, and the Company and
the Subscribers desire to provide hereunder for compliance therewith and for the
possible registration of the shares of Common Stock issuable upon conversion of
the Series G Preferred Stock and/or upon exercise of the Warrants.

          NOW, THEREFORE, in consideration of the premises and the mutual
independent covenants contained herein, the parties hereto, intending to be
legally bound hereby, agree as follows:


                                   ARTICLE I

                                  DEFINITIONS

          1.1  Definitions.  As used in this Agreement, the following
               -----------
capitalized terms have the meanings set forth below:

          Applicable Period - In the case of a Shelf Registration Statement, the
          -----------------
     period referred to in Section 2.1(a)(ii), and in the case of any other
     Registration Statement, nine months or such shorter period as is necessary
     to complete the distribution of the Registrable Securities covered thereby.

          Conversion Shares - The shares of Common Stock (i) issued to Qualified
          -----------------
     Holders upon conversion of shares of Series G Preferred Stock into shares
     of Common Stock, (ii) issued to Qualified Holders upon exercise of the
     Warrants, and (iii) issued as a stock
<PAGE>

     dividend or in a stock split or in connection with any other stock
     combination or division in respect of the Conversion Shares issued upon
     such conversion and/or exercise.

          Demand - As defined in Section 2.1(a)(i) hereof.
          ------

          Exchange Act - The Securities Exchange Act of 1934, as amended, or
          ------------
     similar federal statute then in effect, and a reference to a particular
     section thereof or regulation thereunder shall be deemed to include a
     reference to the comparable section, if any, of, or regulation, if any,
     under, any such similar federal statute.

          Issue Date - The date on which the Series G Preferred Stock and the
          ----------
     Warrants are first issued.

          Majority Holders - Qualified Holders holding a majority of the
          ----------------
     Registrable Securities included in a Shelf Registration Statement.

          Notice of Demand - As defined in Section 2.1(a)(i) hereof.
          ----------------

          Person - An individual, partnership, joint venture, corporation,
          ------
     trust, unincorporated organization or government or any department or
     agency thereof.

          Piggy-back Registration - A registration of Conversion Shares pursuant
          -----------------------
     to Section 2.1(b) hereof.

          Qualified Holder - Each Subscriber so long as it or he holds any of
          ----------------
     the Conversion Shares and each Person to whom a Subscriber or a Qualified
     Holder transfers such Conversion Shares.

          Prospectus - The prospectus included in a Registration Statement,
          ----------
     including any preliminary prospectus, and any such Prospectus as amended or
     supplemented by any prospectus supplement with respect to the terms of the
     offering of any portion of the Registrable Securities covered by a
     Registration Statement, and by all other amendments and supplements to such
     Prospectus, including post-effective amendments, and in each case including
     all exhibits thereto and all material incorporated by reference therein.

          Registrable Securities - Any Conversion Shares issued to, and held by,
          ----------------------
     a Qualified Holder.  As to any Registrable Securities, once issued such
     securities shall cease to be Registrable Securities when (i) a Registration
     Statement with respect to the sale of such securities shall have become
     effective under the Securities Act and such securities shall have been
     disposed of in accordance with such registration statement or, if earlier,
     when the Applicable Period shall have expired with respect to such
     securities; (ii) they shall have been distributed to the public pursuant to
     Rule 144 (or any successor provision) under the Securities Act; (iii) new
     certificates for them not bearing a legend restricting further transfer
     shall have been delivered by the Company and subsequent disposition of them
     shall not require registration or qualification of them under the
     Securities Act or any similar state law then in force; or (iv) they shall
     have ceased to be outstanding.

                                       2
<PAGE>

          Registration Statement - The Shelf Registration Statement, any
          ----------------------
     registration statement registering shares held by Qualified Holders
     pursuant to Section 2.1(b) hereof and all amendments and supplements to any
     such Registration Statement, including post-effective amendments, in each
     case including the Prospectus contained therein, all exhibits thereto and
     all material incorporated by reference therein.

          SEC - The Securities and Exchange Commission.
          ---

          Securities Act - The Securities Act of 1933, as amended, or similar
          --------------
     federal statute then in effect, and a reference to a particular section
     thereof or regulation thereunder shall be deemed to include a reference to
     the comparable section, if any, of, or regulation, if any, under, such
     similar federal statute.

          Seller - As defined in Section 2.1(g) hereof.
          ------

          Shelf Registration - A registration required to be effected pursuant
          ------------------
     to Section 2.1(a).

          Shelf Registration Statement - A "shelf" registration statement of the
          ----------------------------
     Company pursuant to the provisions of Section 2.1(a) of this Agreement
     which covers Registrable Securities and is filed on Form S-3 under Rule 415
     under the Securities Act, or any similar rule that may be adopted by the
     SEC, and all amendments and supplements to such registration statement,
     including post-effective amendments, in each case including the Prospectus
     contained therein, all exhibits thereto and all material incorporated by
     reference therein.

          Underwriter - A person who acts as an underwriter with respect to any
          -----------
     registration of securities pursuant to this Agreement.

          Underwritten Offering - A sale of securities of the Company to an
          ---------------------
     Underwriter or Underwriters for reoffering to the public.


                                  ARTICLE II

                              REGISTRATION RIGHTS

          2.1  Registration.
               ------------

          (a)  Shelf Registration.
               ------------------

               (i)    At any time from the Issue Date until the fifth
          anniversary of the Issue Date, one or more Qualified Holders holding
          in the aggregate at least the number of Conversion Shares equal to ten
          percent of the Conversion Shares that may or have been issued (as
          adjusted for stock splits, stock dividends, reverse stock splits or
          any other combination or division of the Conversion Shares) will be
          entitled

                                       3
<PAGE>

          to deliver to the Company, on one occasion, a written notice (a
          "Demand") requesting a Shelf Registration. Upon receipt of a Demand,
          the Company will deliver to each Qualified Holder a written notice
          (the "Notice of Demand") which shall include a copy of the Demand
          together with a statement to the effect that the Company will include
          all Registrable Securities in a Shelf Registration pursuant to this
          Section 2.1(a) unless the Company receives, by a date specified in the
          Notice of Demand (which shall be no less than 20 days following the
          delivery of such Notice of Demand), a notice from a Qualified Holder
          to exclude all or a portion of such Qualified Holder's Registrable
          Securities from such Shelf Registration. Following receipt of a
          Demand, the Company shall, as expeditiously as reasonably possible,
          use its best efforts to effect a Shelf Registration of all Registrable
          Securities except those which a Qualified Holder has on a timely basis
          requested to be excluded from such Shelf Registration and those of any
          Qualified Holder who does not provide information reasonably requested
          by the Company in connection with the Shelf Registration Statement.
          The Company may, at its option, include in such Shelf Registration
          Statement shares held by any shareholder other than the Qualified
          Holders having rights similar to those contained in this Section
          2.1(a).

               (ii)   The Company agrees to use its best efforts to keep the
          Shelf Registration Statement continuously effective for a period of
          two years following the date on which such Shelf Registration
          Statement is initially declared effective or such shorter period which
          will terminate when all of the Registrable Securities covered by the
          Shelf Registration Statement have been sold pursuant to the Shelf
          Registration Statement. The Company further agrees, if necessary, to
          supplement or amend the Shelf Registration Statement, if required by
          the rules, regulations or instructions applicable to the registration
          form used by the Company for such Shelf Registration Statement or by
          the Securities Act or by any other rules and regulations thereunder
          for shelf registration.

               (iii)  On one occasion, the Majority Holders of the Registrable
          Securities covered by a Shelf Registration Statement may elect to have
          such Registrable Securities sold in an Underwritten Offering. In such
          event, the Company shall be entitled to engage an investment banking
          firm selected by the Company to serve as Underwriter.

          (b)  Piggy-back Registration.
               -----------------------

               (i)    If the Company at any time prior to the seventh
          anniversary of the Issue Date, proposes to register any of its
          securities for an Underwritten Offering under the Securities Act
          (other than pursuant to a Shelf Registration), whether or not for sale
          for its own account, and if the registration form proposed to be used
          may be used for the registration of Registrable Securities, the
          Company will each such time give prompt written notice to all
          Qualified Holders of its intention to do so. Upon the written request
          of any such Qualified Holder made within 30 days after the receipt of
          any such notice (which request shall specify the Registrable
          Securities intended to be disposed of by such Qualified Holder), the
          Company will use its best

                                       4
<PAGE>

          efforts to cause all such Registrable Securities as to which Qualified
          Holders requested registration to be registered under the Securities
          Act (with the securities which the Company at the time proposes to
          register), so as to permit the sale or other disposition by such
          Qualified Holders of such Registrable Securities.

               (ii)   No registration effected pursuant to this Section 2.1(b)
          shall be deemed to have been effected pursuant to Section 2.1(a)
          hereof.

               (iii)  Notwithstanding anything to the contrary in this Section
          2.1(b), the Company shall have the right to discontinue any Piggy-back
          Registration at any time prior to the effective date of such Piggy-
          back Registration if the registration of other securities giving rise
          to such Piggy-back Registration is discontinued; but no such
          discontinuation shall preclude an immediate or subsequent request for
          a Shelf Registration.

          (c)  Registration Procedures.  If the Company is required by the
               -----------------------
     provisions of this Section 2.1 to use its best efforts to effect or cause
     the registration of any Registrable Securities under the Securities Act as
     provided in this Section, the Company will, as expeditiously as possible:

               (i)    prepare and file with the SEC a Registration Statement
          with respect to such Registrable Securities and use its best efforts
          to cause such registration statement to become and remain effective
          during the Applicable Period; in the case of a Shelf Registration
          Statement, such Registration Statement shall be (A) reasonably
          acceptable to special counsel for the Qualified Holders and (B)
          available for the sale of Registrable Securities in accordance with
          the intended method or methods of distribution of the selling
          Qualified Holders (subject to the limitation set forth in Section
          2.1(a)(iii) hereof);

               (ii)   prepare and file with the SEC such amendments and
          supplements to such Registration Statement as may be necessary to keep
          such Registration Statement effective for the Applicable Period and to
          comply with the provisions of the Securities Act with respect to the
          sale or other disposition of all securities covered by such
          Registration Statement during the Applicable Period in accordance with
          the intended methods of disposition by the seller or sellers thereof
          set forth in such Registration Statement;

               (iii)  furnish to each seller of such Registrable Securities and,
          in the case of an Underwritten Offering, each Underwriter of the
          securities being sold by such seller, such number of copies of such
          Registration Statement, such number of copies of the Prospectus
          included in such Registration Statement and such other documents as
          such seller and Underwriter may reasonably request in order to
          facilitate the public sale or other disposition of the Registrable
          Securities owned by such seller (including any Prospectus amended or
          supplemented as set forth in Section 2.1(c)(vi));

                                       5
<PAGE>

               (iv)   use its best efforts to register or qualify such
          Registrable Securities covered by such Registration Statement under
          such other securities or blue sky laws of such jurisdictions as any
          seller and each Underwriter of the securities being sold by such
          seller shall reasonably request, and do any and all other acts and
          things which may be necessary or advisable to enable such seller and
          underwriter to consummate the disposition in such jurisdictions of
          such Registrable Securities owned by such seller; provided, the
          Company shall not for any such purpose be required to (A) qualify
          generally to do business as a foreign corporation in any jurisdiction
          wherein it would not but for the requirements of this Section
          2.1(c)(iv) be obligated to be qualified, (B) subject itself to
          taxation in any such jurisdiction, (C) to consent to general service
          of process in any such jurisdictions, or (D) register or qualify such
          Registrable Securities in more than ten states;

               (v)    use its best efforts to cause such Registrable Securities
          covered by such registration statement to be registered with or
          approved by such other governmental agencies or authorities as may be
          necessary to enable the seller or sellers thereof to consummate the
          disposition of such Registrable Securities;

               (vi)   notify each seller of any such Registrable Securities
          covered by such Registration Statement (i) of the issuance by the SEC
          or any state securities authority of any stop order suspending the
          effectiveness of such Registration Statement or the initiation of any
          proceedings for that purpose, (ii) of receipt of notification with
          respect to the suspension of the qualification of the Registrable
          Securities for offer or sale in any jurisdiction or the initiation of
          any proceeding for such purpose, (iii) at any time when a Prospectus
          relating thereto is required to be delivered under the Securities Act,
          of the Company's becoming aware that the Prospectus included in such
          Registration Statement, as then in effect, includes an untrue
          statement of a material fact or omits to state any material fact
          required to be stated therein or necessary to make the statements
          therein not misleading in the light of the circumstances then existing
          (other than a fact relating to such seller), and promptly use its best
          efforts to prepare a Prospectus supplemented or amended so that, as
          thereafter delivered to the purchasers of such Registrable Securities,
          such Prospectus shall not include an untrue statement of a material
          fact or omit to state a material fact required to be stated therein or
          necessary to make the statements therein not misleading in the light
          of the circumstances then existing;

               (vii)  otherwise use its best efforts to comply with federal and
          state laws and all applicable rules and regulations of the SEC, and
          make available to its security holders, as soon as reasonably
          practicable, an earnings statement which shall satisfy the provisions
          of Section 11(a) of the Securities Act;

               (viii) use its best efforts (A) to cause all such Registrable
          Securities covered by such Registration Statement to be listed on each
          securities exchange on which similar securities issued by the Company
          are then listed, if the listing of such Registrable Securities is then
          permitted under the rules of such exchange or (B) to secure
          designation of all such Registrable Securities covered by such
          registration

                                       6
<PAGE>

          statement as a NASDAQ "national market system security" within the
          meaning of Rule 11Aa2-1 under the Exchange Act or, failing that, to
          secure NASDAQ authorization for such Registrable Securities and,
          without limiting the generality of the foregoing, to arrange for at
          least two market makers to register as such with respect to such
          Registrable Securities with the National Association of Securities
          Dealers;

               (ix)   provide a transfer agent and registrar for all such
          Registrable Securities covered by such registration statement not
          later than the effective date of such registration statement;

               (x)    in the case of an Underwritten Offering, enter into an
          underwriting agreement in customary form and take such other actions
          as Majority Holders shall reasonably request in order to expedite or
          facilitate the disposition of such Registrable Securities;

               (xi)   in the case of an Underwritten Offering, use its best
          efforts to obtain an opinion from the Company's counsel and a "cold
          comfort" letter from the Company's independent public accountants in
          customary form and covering such matters of the type customarily
          covered by such opinions and "cold comfort" letters;

               (xii)  make available for inspection by any seller of such
          Registrable Securities covered by such Registration Statement, by any
          Underwriter participating in any disposition to be effected pursuant
          to such Registration Statement and by any attorney, accountant or
          other agent retained by any such seller or any such Underwriter, all
          pertinent financial and other records, pertinent corporate documents
          and properties of the Company, and cause all of the Company's
          officers, directors and employees to supply all information reasonably
          requested by any such seller, underwriter, attorney, accountant or
          agent in connection with such registration statement; provided,
          however, that all such persons shall agree to standard confidentiality
          provisions regarding all such records, documents and information; and

               (xiii) permit any holder of Registrable Securities which holder,
          in the sole and exclusive judgment, exercised in good faith, of such
          holder, might be deemed to be a controlling person of the Company, to
          participate in the preparation of such registration or comparable
          statement.

     Each Qualified Holder shall be deemed to have agreed by including
     Registrable Securities in a Registration Statement that upon receipt of any
     notice from the Company of the happening of any event of the kind described
     in Section 2.1(c)(vi) hereof, such Qualified Holder will forthwith
     discontinue such Qualified Holder's disposition of Registrable Securities
     pursuant to the Registration Statement covering such Registrable Securities
     until such Qualified Holder's receipt of the copies of the supplemented or
     amended prospectus contemplated by Section 2.1(c)(vi) hereof and, if so
     directed by the Company, will deliver to the Company (at the Company's
     expense) all copies, other than permanent file copies, then in such
     Qualified

                                       7
<PAGE>

     Holder's possession of the Prospectus covering such Registrable Securities
     current at the time of receipt of such notice. In the event the Company
     shall give any such notice, the Applicable Period shall be extended by the
     number of days during the period from and including the date of the giving
     of such notice to and including the date when each seller of any
     Registrable Securities covered by such registration statement shall have
     received the copies of the supplemented or amended prospectus contemplated
     by Section 2.1(c)(vi) hereof.

          If any Registration Statement, Prospectus or comparable statement
     refers to any holder by name or otherwise as the holder of any securities
     of the Company, then (whether or not, in the sole and exclusive judgment,
     exercised in good faith, of such holder, such holder is or might be deemed
     to be a controlling person of the Company) such holder shall have the right
     to require (i) the insertion therein of language, in form and substance
     reasonably satisfactory to such holder and presented to the Company in
     writing, to the effect that the holding of such holder of such securities
     is not to be construed as a recommendation by such holder of the investment
     quality of the Company's securities covered thereby and that such holding
     does not imply that such holder will assist in meeting any future financial
     requirements of the Company, or (ii) in the event that such reference to
     such holder by name or otherwise is not required by the Securities Act or
     any similar federal or state statute then in force, the deletion of the
     reference to such holder.  Each seller shall provide to the Company in
     writing information concerning itself required by law to be included in any
     Registration Statement registering shares held by such seller.

          (d)  Registration Expenses.  The Company shall, whether or not any
               ---------------------
     Shelf Registration or Piggy-back Registration shall become effective, pay
     all expenses incident to its performance of or compliance with this Section
     in connection with a Shelf Registration or Piggy-back Registration,
     including without limitation all registration and filing fees, fees and
     expenses of compliance with securities or blue sky laws (subject to the
     limitation set forth in Section 2.1(c)(iv) hereof), printing expenses,
     messenger and delivery expenses, fees and disbursements of counsel for the
     Company and all independent public accountants (including the expenses of
     any audit and/or "cold comfort" letter) and other persons retained by the
     Company and reasonable fees and disbursements of one counsel or firm of
     counsel chosen by the Majority Holders, and any fees and disbursements of
     underwriters customarily paid by issuers or sellers of securities
     (excluding underwriting commissions and discounts).  In all cases, any
     allocation of Company personnel or other general overhead expenses of the
     Company or other expenses for the preparation of financial statements or
     other data normally prepared by the Company in the ordinary course of its
     business shall be borne by the Company.

          (e)  Indemnification and Contribution. The Company hereby indemnifies,
               --------------------------------
     to the extent permitted by law, each Qualified Holder, its officers and
     directors, if any, and each Person, if any, who controls such Qualified
     Holder within the meaning of Section 15 of the Securities Act, against all
     losses, claims, damages, liabilities (or proceedings in respect thereof)
     and expenses (under the Securities Act or common law or otherwise), joint
     or several, caused by any untrue statement or alleged untrue statement of a
     material fact contained in any Registration Statement or Prospectus (as
     amended or supplemented if the

                                       8
<PAGE>

     Company shall have furnished any amendments or supplements thereto) or
     caused by any omission or alleged omission to state therein a material fact
     required to be stated therein or necessary to make the statements therein
     not misleading, except insofar as such losses, claims, damages, liabilities
     (or proceedings in respect thereof) or expenses are caused by any untrue
     statement or alleged untrue statement contained in or by any omission or
     alleged omission from information respecting such Qualified Holder
     furnished in writing to the Company by such Qualified Holder expressly for
     use therein. If the offering pursuant to any Registration Statement
     provided for under this Section is made through Underwriters, the Company
     agrees to enter into an underwriting agreement in customary form with such
     Underwriters and to indemnify such Underwriters, their officers and
     directors, if any, and each Person, if any, who controls such Underwriters
     within the meaning of Section 15 of the Securities Act, against all losses,
     claims, damages, liabilities (or proceedings in respect thereof) and
     expenses (under the Securities Act or common law or otherwise), joint or
     several, caused by any untrue statement or alleged untrue statement of a
     material fact contained in any Registration Statement or Prospectus (as
     amended or supplemented if the Company shall have furnished any amendments
     or supplements thereto) or caused by any omission or alleged omission to
     state therein a material fact required to be stated therein or necessary to
     make the statements therein not misleading, except insofar as such losses,
     claims, damages, liabilities (or proceedings in respect thereof) or
     expenses are caused by any untrue statement or alleged untrue statement
     contained in or by any omission or alleged omission from information
     respecting such Underwriters or the participating Qualified Holders
     furnished in writing to the Company by such Underwriters or the
     participating Qualified Holders expressly for use therein. In connection
     with any Registration Statement with respect to Registrable Securities held
     by a Qualified Holder, each such Qualified Holder will furnish to the
     Company in writing such information respecting such Qualified Holder as
     shall be reasonably requested by the Company for use in any such
     Registration Statement or Prospectus and will indemnify, to the extent
     permitted by law, the Company, its officers and directors and each Person,
     if any, who controls the Company within the meaning of Section 15 of the
     Securities Act, against any losses, claims, damages, liabilities (or
     proceedings in respect thereof) and expenses resulting from any untrue
     statement or alleged untrue statement of a material fact or any omission or
     alleged omission of a material fact required to be stated in the
     Registration Statement or Prospectus or necessary to make the statements
     therein not misleading, but only to the extent that such untrue statement
     is contained in or such omission is from information so furnished in
     writing by such Qualified Holder expressly for use therein. If the offering
     pursuant to any such Registration Statement is made through Underwriters,
     each such Qualified Holder agrees to enter into an underwriting agreement
     in customary form with such Underwriters, and to indemnify such
     Underwriters, their officers and directors, if any, and each Person, if
     any, who controls such Underwriters within the meaning of Section 15 of the
     Securities Act to the same extent as hereinbefore provided with respect to
     indemnification by such Qualified Holder of the Company. Any Person
     entitled to indemnification under the provisions of this Section 2.1(e)
     shall (i) give prompt notice to the indemnifying party of any claim with
     respect to which it seeks indemnification and (ii) unless in such
     indemnified party's reasonable judgment a conflict of interest between such
     indemnified and indemnifying parties may exist in respect of such claim,
     permit such indemnifying party to assume the defense of such claim, with
     counsel reasonably satisfactory to the indemnified party; and if such
     defense is

                                       9
<PAGE>

     so assumed, such indemnifying party shall not enter into any settlement
     without the consent of the indemnified party if such settlement attributes
     liability to the indemnified party and such indemnifying party shall not be
     subject to any liability for any such settlement made without its consent
     (which consent shall not be unreasonably withheld); and any underwriting
     agreement entered into with respect to any Registration Statement provided
     for under this Section shall so provide. In the event an indemnifying party
     shall not be entitled, or elects not, to assume the defense of a claim,
     such indemnifying party shall not be obligated to pay the fees and expenses
     of more than one counsel or firm of counsel for all parties indemnified by
     such indemnifying party in respect of such claim, unless in the reasonable
     judgment of any such indemnified party a conflict of interest may exist
     between such indemnified party and any other of such indemnified parties in
     respect to such claim. Such indemnity shall remain in full force and effect
     regardless of any investigation made by or on behalf of a participating
     Qualified Holder, its officers, directors or any Person, if any, who
     controls such Qualified Holder as aforesaid, and shall survive the transfer
     of such securities by such Qualified Holder.

     If for any reason the foregoing indemnity is unavailable, or is
     insufficient to hold harmless an indemnified party, then the indemnifying
     party shall contribute to the amount paid or payable by the indemnified
     party as a result of such losses, claims, damages, liabilities or expenses
     (x) in such proportion as is appropriate to reflect the relative benefits
     received by the indemnifying party on the one hand and the indemnified
     party on the other or (y) if the allocation provided by clause (x) above is
     not permitted by applicable law or provides a lesser sum to the indemnified
     party than the amount hereinafter calculated, in such proportion as is
     appropriate to reflect not only the relative benefits received by the
     indemnifying party on the one hand and the indemnified party on the other
     but also the relative fault of the indemnifying party and the indemnified
     party as well as any other relevant equitable considerations.
     Contributions required to be made by an Underwriter, if any, shall be
     governed by the terms of the underwriting agreement.  Notwithstanding the
     foregoing, no person guilty of fraudulent misrepresentation (within the
     meaning of Section 11(f) of the Securities Act) shall be entitled to
     contribution from any person who was not guilty of such fraudulent
     misrepresentation.

          (f)  Certain Limitations on Registration Rights.
               ------------------------------------------

               (i)    In the case of an Underwritten Offering under a Shelf
          Registration, if the Majority Holders determine to enter into an
          underwriting agreement in connection therewith, or, in the case of a
          Piggy-back Registration, if the Company or holders of securities
          initially requesting or demanding such registration have determined to
          enter into an underwriting agreement in connection therewith, all
          Registrable Securities to be included in such registration shall be
          subject to such underwriting agreement, and no Person may participate
          in such registration unless such Person agrees to sell such Person's
          securities on the basis provided in the underwriting arrangements
          approved by the Company or such holders and completes and/or executes
          all questionnaires, powers of attorney, indemnities, underwriting
          agreements and other reasonable documents which must be executed under
          the terms of such underwriting arrangements.

                                       10
<PAGE>

               (ii)   Notwithstanding anything to the contrary in this Section
          2.1, if the Company shall previously have received a request for
          registration under this or any other registration rights agreement,
          and if such previous registrations shall not have been withdrawn or
          abandoned, the Company will not effect any registration of any of its
          securities under the Securities Act (other than a registration on Form
          S-4 or S-8 (or any similar form) or other publicly registered offering
          pursuant to the Securities Act pertaining to the issuance of
          securities under any benefit plan, employee compensation plan, or
          employee or director stock purchase plan or in connection with an
          offer of securities solely to existing security holders) whether or
          not for sale for its own account, until a period of three months shall
          have elapsed from the effective date of such previous registration;
          and the Company shall so provide in any registration rights agreements
          hereafter entered into with respect to any of its securities.

          (g)  Allocation of Securities Included in Registration Statement.  In
               -----------------------------------------------------------
     the case of an Underwritten Offering, if the Company's managing Underwriter
     shall advise the Company and the Qualified Holders in writing that the
     inclusion in any registration pursuant to this Section of some or all of
     the Registrable Securities sought to be registered by the holders
     requesting such registration creates a substantial risk that the proceeds
     or price per unit the Sellers (as defined below) will derive from such
     registration will be reduced or that the number of securities to be
     registered (including those sought to be registered at the instance of the
     Company and any other party entitled to participate in such registration as
     well as those sought to be registered by the Qualified Holders) is too
     large a number to be reasonably sold, then the number of Registrable
     Securities sought to be registered by each Seller shall be reduced pro rata
     in proportion to the number of securities sought to be registered by all
     Sellers to the extent necessary to reduce the number of securities to be
     registered to the number recommended by the managing underwriter.

          For purposes of this Section 2.1(g) the term "Seller" shall mean and
     include the Company and each holder of securities (including, but not
     limited to, Registrable Securities) entitled to participate in the subject
     registration.

          (h)  Limitations on Sale or Distribution of Other Securities.  Each
               -------------------------------------------------------
     holder of Registrable Securities shall be deemed to have agreed by the
     inclusion of Registrable Securities in a Registration Statement not to
     effect any public sale or distribution, including (if requested by the
     Underwriter) any sale pursuant to Rule 144 under the Securities Act, of any
     Registrable Securities, and to use such holder's best efforts not to effect
     any public sale or distribution of any other equity security of the Company
     or of any security convertible into or exchangeable or exercisable for any
     equity security of the Company (other than as part of such underwritten
     public offering) within 7 days before or 90 days (or such other period to
     which the Underwriters of such offering may consent) after the effective
     date of any Registration Statement filed by the Company pursuant to this
     Article II or other agreement providing for registration rights.

                                       11
<PAGE>

          2.2  Rule 144.  The Company covenants that it will timely file the
               --------
reports required to be filed by it under the Securities Act or the Exchange Act
(including but not limited to the reports under Sections 13 and 15(d) of the
Exchange Act referred to in subparagraph (c)(l) of Rule 144 adopted by the SEC
under the Securities Act) and the rules and regulations adopted by the SEC
thereunder (or, if the Company is not required to file such reports, will, upon
the request of any Qualified Holder, make publicly available such information),
and will take such further action as any Qualified Holder may reasonably
request, all to the extent required from time to time to enable such Qualified
Holder to sell Registrable Securities without registration under the Securities
Act within the limitation of the exemptions provided by (i) Rule 144 under the
Securities Act, as such Rule may be amended from time to time, or (ii) any
similar rule or regulation hereafter adopted by the SEC.  Upon the request of
any Qualified Holder, the Company will deliver to such Qualified Holder a
written statement as to whether it has complied with such requirements.


                                  ARTICLE III

                                 MISCELLANEOUS

          3.1  Amendments and Waivers.  The provisions of this Agreement,
               ----------------------
including the provisions of this sentence, may not be amended, modified or
supplemented, and waivers or consents to departures from the provisions hereof
may not be given unless the Company has obtained the written consent of the
Majority Holders; provided, however, that no amendment, modification or
                  --------  -------
supplement or waiver or consent to the departure with respect to the provisions
of Sections 2.1(a) or 2.1(e) hereof shall be effective as against any Holder of
Registrable Securities unless consented to in writing by such Holder of
Registrable Securities.

          3.2  Successors, Assigns and Transferees.  This Agreement shall be
               -----------------------------------
binding upon and shall inure to the benefit of the parties hereto and their
respective representatives, administrators, heirs, successors and assigns, as
applicable, including, without limitation and without the need for an express
assignment, subsequent Qualified Holders.  If any successor, assignee or
transferee of any Qualified Holder shall acquire Registrable Securities, in any
manner, whether by operation of law or otherwise, such Registrable Securities
shall be held subject to all of the terms of this Agreement, and by taking and
holding such Registrable Securities such Person shall be entitled to receive the
benefits hereof and shall be conclusively deemed to have agreed to be bound by
all of the terms and provisions hereof.

          3.3  Notices.  All notices and other communications provided for
               -------
hereunder shall be in writing and shall be sent by first class mail, telex,
facsimile or hand delivery:

                                       12
<PAGE>

          if to the Company, to:

               Allin Corporation
               381 Mansfield Avenue
               Suite 400
               Pittsburgh, PA 15220
               Attention: Richard W. Talarico
               FAX: (412) 928-0225

          if to a Qualified Holder, to:

               the most recent address of such Qualified Holder on the books of
               the Company

     All such notices and communications shall be deemed to have been given or
     made (i) when delivered by hand, (ii) two business days after being
     deposited in the mail, postage prepaid, (iii) when telexed, answer-back
     received or (iv) when sent by facsimile, receipt acknowledged.

          3.4  Descriptive Headings.  The headings in this Agreement are for
               --------------------
convenience of reference only and shall not limit or otherwise affect the
meaning of terms contained herein.

          3.5  Severability.  In the event that any one or more of the
               ------------
provisions, paragraphs, words, clauses, phrases or sentences contained herein,
or the application thereof in any circumstances, is held invalid, illegal or
unenforceable in any respect for any reason, the validity, legality and
enforceability of such provision, paragraph, word, clause, phrase or sentence in
every other respect and of the remaining provisions, paragraphs, words, clauses,
phrases or sentences hereof shall not be in any way impaired, it being intended
that all rights, powers and privileges of the parties hereto shall be
enforceable to the fullest extent permitted by law.

          3.6  Counterparts.  This Agreement may be executed in two or more
               ------------
counterparts, each of which shall be deemed an original, but all of which shall
constitute one and the same instrument, and it shall not be necessary in making
proof of this Agreement to produce or account for more than one such
counterpart.

          3.7  Governing Law.  This Agreement shall be governed by and construed
               -------------
and enforced in accordance with the laws of the State of Delaware, without
regard to the conflicts of laws rules thereof.

                       [signatures appear on next page]

                                       13
<PAGE>

          IN WITNESS WHEREOF, each of the undersigned has executed this
Agreement or caused this Agreement to be executed on its behalf as of the date
first written above.

                              ALLIN CORPORATION


                              By:  /s/ Dean C. Praskach
                                 -----------------------------------------
                              Title:  Secretary
                                    --------------------------------------


                              SUBSCRIBERS:


                                /s/ Henry Posner, Jr.
                              --------------------------------------------



                                /s/ Richard W. Talarico
                              --------------------------------------------



                                /s/ William C. Kavan
                              --------------------------------------------



                                /s/ Dean C. Praskach
                              --------------------------------------------



                                /s/ Thomas D. Wright
                              --------------------------------------------



                                /s/ Thomas D. Wright, Jr.
                              --------------------------------------------



                                /s/ Melissa Dailey Wright
                              --------------------------------------------



                                /s/ Steven B. Wright
                              --------------------------------------------

                                       14