<PAGE>
                                                                    Exhibit 10.1

          STOCKHOLDER AGREEMENT (this "Agreement") dated as of December 16,
2005, among JOHNSON & JOHNSON, a New Jersey corporation ("Parent"), and the
individuals and other parties listed on Schedule A attached hereto (each, a
"Stockholder" and, collectively, the "Stockholders").

          WHEREAS Parent, Emerald Merger Sub, Inc., a Delaware corporation and a
wholly owned Subsidiary of Parent ("Sub"), and Animas Corporation, a Delaware
corporation (the "Company"), propose to enter into an Agreement and Plan of
Merger dated as of the date hereof (as the same may be amended or supplemented,
the "Merger Agreement") providing for the merger of Sub with and into the
Company (the "Merger"), upon the terms and subject to the conditions set forth
in the Merger Agreement;

          WHEREAS each Stockholder owns the number of shares of common stock,
par value $.01 per share, of the Company (the "Company Common Stock"), set forth
opposite his, her or its name on Schedule A attached hereto, together with any
other shares of capital stock of the Company acquired by the Stockholders after
the date hereof and during the term of this Agreement, including through the
exercise of any stock options or similar instruments (such shares of Company
Common Stock being collectively referred to herein as the "Subject Shares" of
such Stockholder);

          WHEREAS the Board of Directors of the Company has approved the terms
of this Agreement as set forth in the Merger Agreement; and

          WHEREAS, as a condition to its willingness to enter into the Merger
Agreement, Parent has requested that each Stockholder enter into this Agreement.

          NOW, THEREFORE, to induce Parent to enter into, and in consideration
of its entering into, the Merger Agreement, and in consideration of the mutual
promises and the representations, warranties, covenants and agreements contained
herein, the parties hereto, intending to be legally bound, agree as follows:

          SECTION 1. Representations and Warranties of Each Stockholder. Each
Stockholder hereby, severally and not jointly, represents and warrants to Parent
as of the date hereof in respect of himself, herself or itself as follows:

          (a) Authority, Execution and Delivery; Enforceability. The Stockholder
has all requisite power and authority to enter into this Agreement and to
consummate the transactions contemplated hereby. This Agreement has been duly
authorized, executed and delivered by the Stockholder and constitutes the legal,
valid and binding obligation of the Stockholder, enforceable against the
Stockholder in accordance with its terms, subject to bankruptcy, insolvency,
moratorium, reorganization or similar laws affecting the rights of creditors
generally and the availability of equitable remedies. Except for the expiration
or termination of the waiting periods under the HSR Act and informational
filings with the SEC, the

<PAGE>

                                                                               2


execution and delivery by the Stockholder of this Agreement do not, and the
consummation of the transactions contemplated hereby and compliance with the
provisions of this Agreement will not, conflict with, or result in any violation
or breach of, or default (with or without notice or lapse of time, or both)
under, or give rise to a right of, or result in, termination, cancellation or
acceleration of any obligation or to the loss of a benefit under, or result in
the creation of any Lien upon any of the Subject Shares of the Stockholder
under, (i) any trust agreement, loan or credit agreement, bond, debenture, note,
mortgage, indenture, lease or other contract, agreement, obligation, commitment,
arrangement, understanding, instrument, permit, franchise or license, whether
oral or written (each, including all amendments thereto, a "Contract"), to which
the Stockholder is a party or any of the Subject Shares of the Stockholder is
subject or (ii) subject to the governmental filings and other matters referred
to in the following sentence, any (A) statute, law, ordinance, rule or
regulation applicable to the Stockholder or the Subject Shares of the
Stockholder or (B) order, writ, injunction, decree, judgment or stipulation
applicable to the Stockholder or the Subject Shares of the Stockholder. No
consent, approval, order or authorization of, action by or in respect of, or
registration, declaration or filing with, any Governmental Entity is required
with respect to the Stockholder that is unique to the Stockholder in connection
with the execution, delivery and performance of this Agreement or the
consummation of the transactions contemplated hereby, except for (i) compliance
with and filings under the HSR Act, if applicable to the Stockholder's receipt
in the Merger of the Merger Consideration, (ii) such reports under Sections
13(d) and 16 of the Exchange Act as may be required in connection with this
Agreement and the transactions contemplated hereby and (iii) where the failure
to obtain such consent, approval, order, authorization or action, or to make
such registration, declaration or filing, could not reasonably be expected to
prevent, materially impede or materially delay the performance by the
Stockholder of its obligations under this Agreement. If the Stockholder is a
natural person and is married, and the Stockholder's Subject Shares constitute
community property or otherwise need spousal or other approval for this
Agreement to be legal, valid and binding, this Agreement has been duly
authorized, executed and delivered by, and constitutes a valid and binding
agreement of, the Stockholder's spouse, enforceable against such spouse in
accordance with its terms. No trust of which such Stockholder is a trustee
requires the consent of any beneficiary to the execution and delivery of this
Agreement or to the consummation of the transactions contemplated hereby.

          (b) The Subject Shares. The Stockholder is the record and beneficial
owner of, or is trustee of a trust that is the record holder of, and whose
beneficiaries are the beneficial owners of, and has good and marketable title
to, the Subject Shares set forth opposite his, her or its name on Schedule A
attached hereto, free and clear of any Liens. The Stockholder has the sole right
to vote such Subject Shares (except to the extent that such Subject Shares are
issuable upon the exercise of options that have not been exercised by such
Stockholder), and, except as contemplated by this Agreement, none of such
Subject Shares is subject to any voting trust or other agreement, arrangement or
restriction with respect to the voting of such Subject Shares.

<PAGE>

                                                                               3


          SECTION 2. Representations and Warranties of Parent. Parent hereby
represents and warrants to each Stockholder that Parent (i) is duly
incorporated, validly existing and in good standing under the laws of the State
of New Jersey, (ii) has all requisite corporate power and authority to execute
and deliver the Merger Agreement and to consummate the transactions contemplated
thereby and (iii) has all requisite corporate power and authority to execute and
deliver this Agreement and to consummate the transactions contemplated hereby.
The execution and delivery by Parent of this Agreement and consummation of the
transactions contemplated hereby have been duly authorized by all necessary
corporate action on the part of Parent. Parent has duly executed and delivered
this Agreement, and, assuming this Agreement constitutes the legal, valid and
binding obligation of each of the other parties hereto, this Agreement
constitutes a legal, valid and binding obligation of Parent enforceable against
Parent in accordance with its terms, subject to bankruptcy, insolvency,
moratorium, reorganization or similar laws affecting the rights of creditors
generally and the availability of equitable remedies. The execution and delivery
by Parent of this Agreement do not, and the consummation of the transactions
contemplated hereby and compliance with the terms of this Agreement will not,
conflict with, or result in any violation or breach of, or default (with or
without notice or lapse of time, or both) under, or give rise to a right of, or
result in, termination, cancellation or acceleration of any obligation or to the
loss of a benefit under, (i) the Certificate of Incorporation or By-laws of
Parent, (ii) any Contract to which Parent is a party or any properties or assets
of Parent are subject, in any way that would prevent, materially impede or
materially delay the consummation by Parent of the transactions contemplated by
this Agreement or (iii) subject to the filings and other matters referred to in
the following sentence, any provision of any (A) statute, law, ordinance, rule
or regulation applicable to Parent or the properties or assets of Parent or (B)
order, writ, injunction, decree, judgment or stipulation applicable to Parent or
the properties or assets of Parent, and in each case in any way that would
prevent, materially impede or materially delay the consummation by Parent of the
transactions contemplated by this Agreement. No material consent, approval,
order or authorization of, action by or in respect of, or registration,
declaration or filing with, any Governmental Entity is required by or with
respect to Parent in connection with the execution, delivery and performance of
this Agreement or the consummation of the transactions contemplated hereby,
except for such reports under Sections 13(d) and 16 of the Exchange Act as may
be required in connection with this Agreement and the transactions contemplated
hereby.

          SECTION 3. Covenants of each Stockholder. Each Stockholder, acting as
a stockholder of the Company and not as an officer or director of the Company,
severally and not jointly, agrees as follows:

          (a) Without in any way limiting each Stockholder's right to vote its
Subject Shares in its sole discretion with respect to any other matters, at any
meeting of stockholders of the Company called to vote upon the Merger and the
Merger Agreement or at any adjournment thereof or in any other circumstances
upon which a vote, consent or other approval (including by written consent) with
respect to the Merger and the Merger Agreement is sought, the Stockholder shall,
including by executing a written consent if requested by Parent, vote (or cause
to be voted) the Subject Shares in favor of the Merger, the adoption by the
Company of the Merger

<PAGE>

                                                                               4


Agreement and the approval of the terms thereof and each of the other
transactions contemplated by the Merger Agreement.

          (b) At any meeting of stockholders of the Company or at any
adjournment thereof or in any other circumstances upon which the Stockholder's
vote, consent or other approval is sought, the Stockholder shall vote (or cause
to be voted) the Subject Shares against (i) any merger agreement or merger
(other than the Merger Agreement and the Merger), consolidation, business
combination, recapitalization, liquidation, dissolution, joint venture, binding
share exchange, sale of substantial assets reorganization, or winding up of or
by the Company or any other Takeover Proposal or (ii) any amendment of the
Company Certificate or Amended and Restated By-laws or other proposal or
transaction involving the Company, which amendment or other proposal or
transaction would in any manner impede, frustrate, prevent or nullify, or result
in a breach of any covenant, representation or warranty or any other obligation
of the Company under or with respect to, the Merger, the Merger Agreement or any
of the other transactions contemplated by the Merger Agreement or change in any
manner the voting rights of the Company Common Stock. The Stockholder shall not
commit or agree to take any action inconsistent with the foregoing.

          (c) The Stockholder shall not (i) sell, transfer, pledge, assign or
otherwise dispose of (including by gift) (collectively, "Transfer"), consent to
any Transfer of, or enter into any Contract, option or other arrangement
(including any profit sharing arrangement) with respect to the Transfer of, any
Subject Shares (or any interest therein) to any person other than pursuant to
the terms of the Merger or (ii) enter into any voting arrangement, whether by
proxy, voting agreement or otherwise, with respect to any Subject Shares other
than pursuant to this Agreement and shall not commit or agree to take any of the
foregoing actions. The Stockholder shall not, nor shall such Stockholder permit
any entity under such Stockholder's control to, deposit any Subject Shares in a
voting trust. Nothing contained in this Section 3(c) shall prohibit any sale,
transfer or assignment of Subject Shares by a Stockholder that is a natural
person to members of such Stockholder's family, a family trust of such
Stockholder or a charitable institution or, by a Stockholder that is a family
trust to a grantor or a beneficiary of that trust, if, in each case, the
transferee of such Subject Shares agrees in writing to be bound by the terms
hereof and notice of such sale, transfer or assignment, including the name and
address of the purchaser, transferee or assignee, is delivered to Parent prior
to such sale, transfer or assignment.

          (d) The Stockholder shall not, nor shall it authorize or permit (to
the extent that it has the power not to permit) any employees or Affiliates of,
or any investment banker, financial advisor, attorney, accountant or other
advisor, agent or representative of, the Stockholder (collectively, the
"Stockholder Representatives") to, directly or indirectly through any person or
entity, (i) solicit, initiate or encourage, or take any other action designed
to, or which would reasonably be expected to, facilitate, any inquiries or the
making of any proposal that constitutes or would reasonably be expected to lead
to a Takeover Proposal or (ii) enter into, continue or otherwise participate in
any discussions or negotiations regarding, or furnish to any person any
information with respect to any Takeover Proposal. Without limiting the
foregoing, it

<PAGE>

                                                                               5


is agreed that any violation of the restrictions set forth in the preceding
sentence by any Stockholder Representative of such Stockholder shall be a breach
of this Section 3(d) by such Stockholder. The Stockholder shall promptly advise
Parent orally and in writing of any Takeover Proposal or inquiry made to the
Stockholder with respect to any Takeover Proposal.

          (e) Until the earlier of (i) the consummation of the Merger and (ii)
termination of the Merger Agreement pursuant to its terms, the Stockholder shall
use his, hers or its reasonable efforts to take, or cause to be taken, all
actions, and to do, or cause to be done, and to assist and cooperate with the
other parties in doing, all things necessary, proper or advisable to consummate
and make effective, in the most expeditious manner practicable, the Merger and
the other transactions contemplated by the Merger Agreement. The Stockholder
shall not issue any press release or make any other public statement with
respect to this Agreement, the Merger Agreement, the Merger or any other
transaction contemplated by this Agreement or the Merger Agreement without the
prior written consent of Parent, except as may be required by applicable law.

          (f) The Stockholder, and any beneficiary of a revocable trust for
which such Stockholder serves as trustee, shall not take any action to revoke or
terminate such trust or take any other action which would restrict, limit or
frustrate in any way the transactions contemplated by this Agreement. Each such
beneficiary hereby acknowledges and agrees to be bound by the terms of this
Agreement applicable to it.

          (g) The Stockholder hereby consents to and approves the actions taken
by the Board of Directors of the Company in approving the Merger Agreement and
this Agreement, the Merger and the other transactions contemplated by the Merger
Agreement. The Stockholder hereby waives, and agrees not to exercise or assert,
any appraisal or similar rights under Section 262 of the DGCL or other
applicable law in connection with the Merger.

          SECTION 4. Grant of Irrevocable Proxy; Appointment of
Attorney-in-Fact.

          (a) Each Stockholder hereby irrevocably grants to, and appoints,
Parent and Richard S. Dakers, James J. Bergin and Steven M. Rosenberg, in their
respective capacities as officers or authorized representatives of Parent, and
any individual who shall hereafter succeed to any such office of Parent, and
each of them individually, and any individual designated in writing by any of
them, as such Stockholder's proxy and attorney-in-fact (with full power of
substitution), for and in the name, place and stead of such Stockholder, to vote
such Stockholder's Subject Shares, or grant a consent or approval in respect of
such Subject Shares (i) in favor of adoption of the Merger Agreement and
approval of the Merger and any other transactions contemplated by the Merger
Agreement, (ii) against any Takeover Proposal and (iii) against any amendment of
the Company Certificate or Amended and Restated By-laws, or other proposal or
transaction (including any consent solicitation to remove or elect any directors
of the Company) involving the Company, which amendment or other

<PAGE>

                                                                               6


proposal or transaction would in any manner impede, frustrate, prevent or
nullify, or result in a breach of any covenant, representation or warranty or
any other obligation or agreement of the Company under or with respect to, the
Merger, the Merger Agreement or any of the other transactions contemplated by
the Merger Agreement or change in any manner the voting rights of the Company
Common Stock. The Stockholder understands and acknowledges that Parent is
entering into the Merger Agreement in reliance upon the Stockholder's execution
and delivery of this Agreement.

          (b) Such Stockholder represents that any proxies heretofore given in
respect of such Stockholder's Subject Shares are not irrevocable, and that all
such proxies are hereby revoked.

          (c) Such Stockholder hereby affirms that the irrevocable proxy set
forth in this Section 4 is given in connection with the execution of the Merger
Agreement, and that such irrevocable proxy is given to secure the performance of
the duties of the Stockholder under this Agreement. Such Stockholder hereby
further affirms that the irrevocable proxy is coupled with an interest and may
under no circumstances be revoked. Such Stockholder hereby ratifies and confirms
all that such irrevocable proxy may lawfully do or cause to be done by virtue
hereof. Such irrevocable proxy is executed and intended to be irrevocable in
accordance with the provisions of Section 212(e) of the DGCL. The irrevocable
proxy granted hereunder shall automatically terminate upon the termination of
this Agreement in accordance with Section 7.

          SECTION 5. Further Assurances. Each Stockholder will, from time to
time, execute and deliver, or cause to be executed and delivered, such
additional or further consents, documents and other instruments as Parent may
reasonably request for the purpose of effectively carrying out the transactions
contemplated by this Agreement.

          SECTION 6. Additional Matters. (a) Each Stockholder agrees that this
Agreement and the obligations hereunder shall attach to such Stockholder's
Subject Shares and shall be binding upon any person or entity to which legal or
beneficial ownership of such Subject Shares shall pass, whether by operation of
law or otherwise, including such Stockholder's heirs, guardians, administrators
or successors, and that each certificate representing such Subject Shares will
be inscribed with a legend to such effect. In the event of any stock split,
stock dividend, merger, reorganization, recapitalization or other change in the
capital structure of the Company affecting the Company Common Stock, or the
acquisition of additional shares of Company Common Stock or other voting
securities of the Company by any Stockholder, the number of Subject Shares
listed in Schedule A beside the name of such Stockholder shall be adjusted
appropriately, and this Agreement and the obligations hereunder shall attach to
any additional shares of Company Common Stock or other voting securities of the
Company issued to or acquired by such Stockholder. Notwithstanding any provision
in this Agreement to the contrary, nothing herein shall require or be deemed to
require the exercise of, or give any person other than the Stockholder the power
to exercise, any option to purchase Company Common Stock.

<PAGE>

                                                                               7


          (b) Each Stockholder agrees that such Stockholder will tender to the
Company, within 10 business days after the date hereof (or, in the event Subject
Shares are acquired subsequent to the date hereof within 10 business days after
the date of such acquisition), any and all certificates representing such
Stockholder's Subject Shares in order that the Company may inscribe upon such
certificates the legend in accordance with Section 5.10 of the Merger Agreement.

          (c) No person executing this Agreement who is or becomes during the
term hereof a director or officer of the Company makes (or shall be deemed to
have made) any agreement or understanding herein in his or her capacity as such
a director or officer of the Company. Each Stockholder signs solely in his, her
or its capacity as the record holder and beneficial owner of, or the trustee of
a trust whose beneficiaries are the beneficial owners of, such Stockholder's
Subject Shares and nothing herein shall limit or affect any actions taken by any
Stockholder or any employee or Affiliate of any Stockholder in his or her
capacity as an officer or director of Company to the extent not prohibited by
the Merger Agreement.

          SECTION 7. Termination. This Agreement shall terminate, and the
provisions hereof shall be of no further force or effect, upon the earliest to
occur of (i) the Effective Time, (ii) the termination of the Merger Agreement or
(iii) at the option of any Stockholder, the execution or granting of any
amendment, modification, change or waiver with respect to the Merger Agreement
subsequent to the date of this Agreement that results in any decrease in the
price to be paid per share for the shares of Company Common Stock. Nothing in
this Section 7 shall relieve or otherwise limit the liability of any party for
breach of this Agreement.

          SECTION 8. General Provisions. (a) Amendments. This Agreement may not
be amended except by an instrument in writing signed by each of the parties
hereto.

          (b) Notice. All notices, requests, claims, demands and other
communications hereunder shall be in writing and shall be deemed given if
delivered personally, telecopied (which is confirmed) or sent by overnight
courier (providing proof of delivery) to Parent in accordance with Section 8.02
of the Merger Agreement and to the Stockholders at their respective addresses
set forth on Schedule A attached hereto (or at such other address for a party as
shall be specified by like notice).

          (c) Interpretation. When a reference is made in this Agreement to a
Section or Schedule, such reference shall be to a Section of or a Schedule to,
this Agreement unless otherwise indicated. The headings contained in this
Agreement are for reference purposes only and shall not affect in any way the
meaning or interpretation of this Agreement. Wherever the words "include",
"includes" or "including" are used in this Agreement, they shall be deemed to be
followed by the words "without limitation". The words "hereof", "herein" and
"hereunder" and words of similar import when used in this Agreement shall refer
to this Agreement as a whole and not to any particular provision of this
Agreement.

<PAGE>

                                                                               8


          (d) Counterparts. This Agreement may be executed in one or more
counterparts (including by facsimile), all of which shall be considered one and
the same agreement. This Agreement shall become effective against Parent when
one or more counterparts have been signed by Parent and delivered to each
Stockholder. This Agreement shall become effective against any Stockholder when
one or more counterparts have been executed by such Stockholder and delivered to
Parent. Each party need not sign the same counterpart.

          (e) Entire Agreement; No Third-Party Beneficiaries. This Agreement
(including the documents and instruments referred to herein) (i) constitutes the
entire agreement and supersedes all prior agreements and understandings, both
written and oral, among the parties with respect to the subject matter hereof
and (ii) is not intended to confer upon any person other than the parties hereto
any legal or equitable rights or remedies.

          (f) GOVERNING LAW; CAPITALIZED TERMS. THIS AGREEMENT SHALL BE GOVERNED
BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF DELAWARE,
REGARDLESS OF THE LAWS THAT MIGHT OTHERWISE GOVERN UNDER APPLICABLE PRINCIPLES
OF CONFLICTS OF LAW THEREOF. CAPITALIZED TERMS USED BUT NOT DEFINED HEREIN SHALL
HAVE THE MEANINGS SET FORTH IN THE MERGER AGREEMENT.

          (g) Voidability. If prior to the execution hereof, the Board of
Directors of the Company shall not have duly and validly authorized and approved
by all necessary corporate action, this Agreement, the Merger Agreement and the
transactions contemplated hereby and thereby, so that by the execution and
delivery hereof Parent or Sub would become, or could reasonably be expected to
become an "interested stockholder" with whom the Company would be prevented for
any period pursuant to Section 203 of the DGCL from engaging in any "business
combination" (as such terms are defined in Section 203 of the DGCL), then this
Agreement shall be void and unenforceable until such time as such authorization
and approval shall have been duly and validly obtained.

          SECTION 9. Specific Enforcement; Consent to Jurisdiction. The parties
agree that irreparable damage would occur and that the parties would not have
any adequate remedy at law in the event that any of the provisions of this
Agreement were not performed in accordance with their specific terms or were
otherwise breached. It is accordingly agreed that the parties shall be entitled
to an injunction or injunctions to prevent breaches of this Agreement and to
enforce specifically the terms and provisions of this Agreement in any Federal
court located in the State of Delaware or in any state court in the State of
Delaware, this being in addition to any other remedy to which they are entitled
at law or in equity. In addition, each of the parties hereto (i) consents to
submit itself to the personal jurisdiction of any Federal court located in the
State of Delaware or of any state court located in the State of Delaware in the
event any dispute arises out of this Agreement or the transactions contemplated
by this Agreement, (ii) agrees that it will not attempt to deny or defeat such
personal jurisdiction by motion

<PAGE>

                                                                               9


or other request for leave from any such court and (iii) agrees that it will not
bring any action relating to this Agreement or the transactions contemplated by
this Agreement in any court other than a Federal court located in the State of
Delaware or a state court located in the State of Delaware.

          SECTION 10. Assignment. Subject to Section 3(c), neither this
Agreement nor any of the rights, interests or obligations hereunder shall be
assigned, in whole or in part, by any Stockholder, on the one hand, without the
prior written consent of Parent nor by Parent, on the other hand, without the
prior written consent of the Stockholders, and any assignment without such
consent shall be null and void, except that Parent may assign, in its sole
discretion, any or all of its rights, interests and obligations hereunder to any
direct or indirect wholly owned Subsidiary of Parent. Subject to the preceding
sentence, this Agreement will be binding upon, inure to the benefit of and be
enforceable by the parties and their respective successors and assigns.

          SECTION 11. Waiver of Jury Trial. Each of the parties hereto hereby
waives, to the fullest extent permitted by applicable law, any right it may have
to a trial by jury in respect of any suit, action or other proceeding arising
out of this Agreement. Each party hereto (a) certifies that no representative,
agent or attorney of any other party has represented, expressly or otherwise,
that such party would not, in the event of any action, suit or proceeding, seek
to enforce the foregoing waiver and (b) acknowledges that it and the other
parties hereto have been induced to enter into this Agreement, by, among other
things, the mutual waiver and certifications in this Section 11.

          SECTION 12. Severability. If any term or other provision of this
Agreement is invalid, illegal or incapable of being enforced by any rule of law
or public policy, all other conditions and provisions of this Agreement shall
nevertheless remain in full force and effect. Upon such determination that any
term or other provision is invalid, illegal or incapable of being enforced, the
parties hereto shall negotiate in good faith to modify this Agreement so as to
effect the original intent of the parties as closely as possible to the fullest
extent permitted by applicable law in an acceptable manner to the end that the
transactions contemplated hereby are fulfilled to the extent possible.

<PAGE>

                                                                              10


          IN WITNESS WHEREOF, Parent has caused this Agreement to be signed by
its officer thereunto duly authorized and each Stockholder has signed this
Agreement, all as of the date first written above.

                                        JOHNSON & JOHNSON,


                                        by /s/ John A. Papa
                                           -------------------------------------
                                        Name: John A. Papa
                                        Title: Treasurer

                  [Signature pages of the Stockholders follow]

<PAGE>

                                                                              11


                                        LIBERTY VENTURES I, L.P.

                                        By: Liberty Ventures, Inc.
                                            Its General Partner


                                        By: /s/ Thomas R. Morse
                                            ------------------------------------
                                            Thomas R. Morse
                                            President


                                        LIBERTY VENTURES II, L.P.

                                        By: Liberty Venture Partners II, LLC,
                                            Its General Partner


                                        By: /s/ Thomas R. Morse
                                            ------------------------------------
                                            Thomas R. Morse
                                            Managing Director


                                        LIBERTY ADVISORS, INC.


                                        By: /s/ Thomas R. Morse
                                            ------------------------------------
                                            Thomas R. Morse
                                            President

<PAGE>

                                                                              12


                                        HLM/UH FUND, L.P.

                                        By: HLM/UH Associates, LLC
                                            Its General Partner

                                        By: HLM Management Co., Inc.
                                            Managing Member


                                        By: /s/ Edward L. Cahill
                                            ------------------------------------
                                            Edward L. Cahill
                                            Executive Vice President


                                        HLM OPPORTUNITIES FUND, L.P.

                                        By: HLM Opportunities Associates, LLC
                                            Its General Partner

                                        By: HLM Management Co., Inc.
                                            Managing Member


                                        By: /s/ Edward L. Cahill
                                            ------------------------------------
                                            Edward L. Cahill
                                            Executive Vice President


                                        HLM/CB FUND II, L.P.

                                        By: HLM/CB Associates II, LLC
                                            Its General Partner

                                        By: HLM Management Co., Inc.
                                            Managing Member


                                        By: /s/ Edward L. Cahill
                                            ------------------------------------
                                            Edward L. Cahill
                                            Executive Vice President

<PAGE>

                                                                              13


                                        /s/ Katherine D. Crothall
                                        ----------------------------------------
                                        Katherine D. Crothall


                                        KATHERINE D. CROTHALL GRANTOR
                                        RETAINED ANNUITY TRUST


                                        By: /s/ Katherine D. Crothall
                                            ------------------------------------
                                            Katherine D. Crothall


                                        KAREN L. LAAKMANN TRUST


                                        By: /s/ Katherine D. Crothall
                                            ------------------------------------
                                            Katherine D. Crothall
                                            Trustee


                                        CHRISTINE LAAKMANN TRUST


                                        By: /s/ Katherine D. Crothall
                                            ------------------------------------
                                            Katherine D. Crothall
                                            Trustee


                                        GAYLE R. LAAKMANN TRUST


                                        By: /s/ Katherine D. Crothall
                                            ------------------------------------
                                            Katherine D. Crothall
                                            Trustee


                                        PETER D. LAAKMANN TRUST


                                        By: /s/ Katherine D. Crothall
                                            ------------------------------------
                                            Katherine D. Crothall
                                            Trustee

<PAGE>

                                                                              14


                                        /s/ Graeme Crothall
                                        ----------------------------------------
                                        Graeme Crothall

<PAGE>

                                                                              15


                                        /s/ William A. Graham, IV
                                        ----------------------------------------
                                        William A. Graham, IV


                                        TRUST UNDER AGREEMENT OF WILLIAM A.
                                        GRAHAM, V DATED MARCH 16, 2000


                                        By: /s/ William A. Graham, IV
                                            ------------------------------------
                                            William A. Graham, IV
                                            Attorney-in-fact for William A.
                                            Graham, V


                                        TRUST UNDER AGREEMENT OF LAURA M.
                                        GRAHAM DATED JUNE 19, 2000


                                        By: /s/ William A. Graham, IV
                                            ------------------------------------
                                            William A. Graham, IV
                                            Attorney-in-fact for Laura M. Graham

<PAGE>

                                                                              16


                                        /s/ A. Peter Parsons
                                        ----------------------------------------
                                        A. Peter Parsons


                                        KATHERINE D. CROTHALL 1999
                                        DESCENDENTS TRUST


                                        By: /s/ A. Peter Parsons
                                            ------------------------------------
                                            A. Peter Parsons
                                            Trustee for the Katherine D.
                                            Crothall 1999 Descendents Trust

<PAGE>

                                                                              17


                                        DEED OF TRUST OF WILLIAM A. GRAHAM, IV,
                                        SETTLOR, DATED MAY 29, 1996, FRANCES R.
                                        GRAHAM, REGINA O. THOMAS, TRUSTEES,
                                        EIN: 23-7829976


                                        By: /s/ Regina O. Thomas
                                            ------------------------------------
                                            Regina O. Thomas
                                            Trustee under Deed of Trust of
                                            William A. Graham, IV, Settlor,
                                            dated May 29, 1996


                                        DEED OF TRUST OF WILLIAM A. GRAHAM, IV,
                                        SETTLOR, DATED JULY 27, 1998, FRANCES R.
                                        GRAHAM, REGINA O. THOMAS, TRUSTEES,
                                        EIN: 23-7987961


                                        By: /s/ Regina O. Thomas
                                            ------------------------------------
                                            Regina O. Thomas
                                            Trustee under Deed of Trust of
                                            William A. Graham, IV, Settlor,
                                            dated July 27, 1998

<PAGE>

                                                                              18


                                        GRAEME A. CROTHALL GRANTOR
                                        RETAINED ANNUITY TRUST


                                        By: /s/ Graeme A. Crothall
                                            ------------------------------------
                                            Graeme A. Crothall


                                        GRAEME A. CROTHALL 1999
                                        DESCENDENTS TRUST


                                        By: /s/ Graeme A. Crothall
                                            ------------------------------------
                                            Graeme A. Crothall
                                            Trustee for the Graeme A. Crothall
                                            1999 Descendents Trust

<PAGE>

                                   SCHEDULE A

<TABLE>
<CAPTION>
                                                                    NUMBER OF
                                                                    SHARES OF
                  NAME AND ADDRESS                                 COMMON STOCK
                   OF STOCKHOLDER                                OWNED OF RECORD
                  ----------------                               ---------------
<S>                                                              <C>
Katherine D. Crothall                                               1,238,917
Katherine D. Crothall Grantor Retained Annuity Trust                  266,667
Graeme Crothall                                                       336,833
Peter D. Laakmann Trust                                                92,711
Karen L. Laakmann Trust                                                92,711
Christine Laakmann Trust                                               92,711
Gayle R. Laakmann Trust                                                92,711
William A. Graham, IV                                               1,437,587
Trust Under Agreement of William A. Graham, V Dated                   149,111
March 16, 2000
Trust Under Agreement of Laura M. Graham Dated June 19, 2000          149,111
Deed of Trust of William A. Graham, IV, Settlor,                       20,759
dated May 29, 1996, Frances R. Graham, Regina O.
Thomas, Trustees, EIN: 23-7829976
Deed of Trust of William A. Graham, IV, Settlor,                       35,640
dated July 27, 1998, Frances R. Graham, Regina O.
Thomas, Trustees,
EIN: 23-7987961
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
                                                                    NUMBER OF
                                                                    SHARES OF
                  NAME AND ADDRESS                                 COMMON STOCK
                   OF STOCKHOLDER                                OWNED OF RECORD
                  ----------------                               ---------------
<S>                                                              <C>
Graham A. Crothall Grantor Retained Annuity Trust                     133,334
HLM/UH Fund, L.P.                                                     541,132
HLM/CB Fund II, L.P.                                                  225,471
HLM Opportunities Fund, L.P.                                          135,282
Liberty Advisors, Inc.                                                  1,837
Liberty Ventures I, L.P.                                              285,073
Liberty Ventures II, L.P.                                             285,073
A. Peter Parsons                                                        4,800
Katherine D. Crothall 1999 Descendents Trust                          351,422
Graeme A. Crothall 1999 Descendents Trust                             184,500
                                                                    ---------
   Total                                                            6,153,393
</TABLE>