<PAGE>   1
                                                                   EXHIBIT 10.43



                          REGISTRATION RIGHTS AGREEMENT


                  THIS REGISTRATION RIGHTS AGREEMENT (this "Agreement") is made
as of this 6th day of January 2000, by and among BroadbandNOW, Inc., a Delaware
corporation (the "Company") and Marcus & Partners, L.P., a Delaware limited
partnership (the "Purchaser").

                              W I T N E S S E T H:

                  WHEREAS, the Purchaser and the Company are parties to that
certain Subscription Agreement, dated as of January 6, 2000, whereby the
Purchaser shall purchase, and the Company shall issue and sell, a Warrant to
purchase 300,000 shares of Class A Common Stock, par value $0.001 per share, of
the Company (the "Warrant"); and

                  WHEREAS, in connection with the purchase of such Warrant, the
Company desires to grant to the Purchaser certain registration rights.

                  NOW, THEREFORE, in consideration of the premises herein
contained and other good and valuable consideration, the receipt and sufficiency
of which are hereby acknowledged, the parties hereto agree as follows:

         1. DEFINITIONS. As used in this Agreement, the following terms shall
have the following respective meanings:

                  (a) "Commission" shall mean the United States Securities and
Exchange Commission, or any other federal agency at the time administering the
Securities Act.

                  (b) "Common Stock" shall mean the Company's Class A Common
Stock, par value $0.001 per share, as authorized on the date of this Agreement
or class of common stock issued in exchange therefor.

                  (c) "Conversion Shares" shall mean the shares of Common Stock
issued or issuable upon the exercise of the Warrant.

                  (d) "Exchange Act" shall mean the Securities Exchange Act of
1934, as amended, or any similar federal statute, and the rules and regulations
of the Commission thereunder, all as the same shall be in effect at the time.

                  (e) "Forms S-1, S-2, S-3 and S-4" shall mean the forms so
designated, promulgated by the Commission for registration of securities under
the Securities Act, and any forms succeeding to the functions of such forms,
whether or not bearing the same designation.

                  (f) "Initial Public Offering" shall mean the initial
underwritten offering by the Company for its own account of Common Stock under
the Securities Act.

                  (g) "Person" shall mean an individual, a corporation, a
partnership, a limited liability company, a joint venture, a trust, an estate,
an unincorporated organization, a government or any agency or political
subdivision thereof.



<PAGE>   2

                  (h) "Preferred Stock" shall mean the Company's Series A
Convertible Preferred Stock as designated in its Certificate of Designation.

                  (i) "Preferred Rights Agreements" shall mean the First Amended
and Restated Registration Rights Agreement dated January 25, 2000 between the
Company and the holders of Preferred Stock.

                  (j) "Register," "registered" and "registration" refers to a
registration effected by filing a registration statement in compliance with the
Securities Act and the declaration or ordering by the Commission of
effectiveness of such registration statement.

                  (k) "Registrable Securities" shall mean (i) Conversion Shares
held by (x) the Purchaser, (y) a permitted purchaser of the Warrant pursuant to
its terms, or (z) a Person to whom registration rights have been properly
transferred and (ii) all shares of Common Stock issued b the Company in respect
of the Warrant.

                  (l) "Required Demand Amount" shall mean at least 250,000
shares of the Registrable Securities then outstanding with respect to the
registration effected pursuant to Section 2.

                  (m) "Securities Act" shall mean the Securities Act of 1933, as
amended, or any similar federal statute, and the rules and regulations of the
Commission thereunder, all as the same shall be in effect at the time.

         2. REQUIRED REGISTRATION.

                  (a) Subject to the provisions of Section 4 hereof, the
Purchaser may request the Company in writing to effect under the Securities Act
a registration, stating the number of shares of Registrable Securities to be
disposed of by such Purchaser and the intended method of disposition; provided,
however, that the number of shares requested to be registered by the Purchaser
is at least the Required Demand Amount and the Company can effect such
registration on Form S-3.

                  (b) Subject to the limitations set forth in Section 4 hereof,
the Company will use commercially reasonable efforts to effect the registration
under the Securities Act of all shares of Registrable Securities specified in
the request of the Purchaser; provided, however, that the number of shares
requested to be registered by the Purchaser is at least the Required Demand
Amount and the Company can effect such registration on Form S-3.

         3. REGISTRATION PROCEDURES. Whenever the Company is required by the
provisions of this Agreement to use commercially reasonable efforts to effect
promptly the registration of shares of Registrable Securities, the Company will
use commercially reasonable efforts to:

                  (a) prepare and file with the Commission (i) a registration
statement on Form S-3 with respect to such Registrable Securities, if the
Company meets such eligibility requirements; provided, however, if for any
reason, the Company does not qualify for Form S-3 within 18 months of
registration of the Company's Common Stock under the Exchange Act, then Company
shall file a registration statement on Form S-1 or, if eligible, Form S-2 and
(ii) such


                                       2

<PAGE>   3

amendments and post-effective amendments to the registration statement as may be
necessary to keep the registration statement effective for the period necessary
to complete the proposed distribution; cause the prospectus to be supplemented
by any required prospectus supplement, and as so supplemented to be filed
pursuant to Rule 424 under the Securities Act, and to comply fully with the
applicable provisions of Rules 424 and 430A under the Securities Act in a timely
manner; and comply with the provisions of the Securities Act with respect to the
disposition of all securities covered by such registration statement during the
applicable period in accordance with the intended method or methods of
distribution by the sellers thereof set forth in such registration statement or
supplement to the prospectus;

                  (b) keep such registration statement continuously effective
for the period necessary to complete the proposed distribution but for no longer
than one hundred eighty (180) days subsequent to the effective date of such
registration; upon the occurrence of any event that would cause the registration
statement or the prospectus contained therein to contain a material misstatement
or omission, the Company shall use commercially reasonable efforts to file as
promptly as practicable an appropriate amendment to such registration statement
correcting any such misstatement or omission;

                  (c) advise the underwriter(s), if any, and selling Purchaser
promptly and, if requested by such Persons, to confirm such advice in writing,
(i) when the prospectus or any prospectus supplement or post-effective amendment
has been filed, and, with respect to the registration statement or any
post-effective amendment thereto, when the same has become effective, (ii) of
any request by the Commission for amendments to the registration statement or
amendments or supplements to the prospectus or for additional information
relating thereto, (iii) of the issuance by the Commission of any stop order
suspending the effectiveness of the registration statement under the Securities
Act or of the suspension by any state securities commission of the qualification
of the Registrable Securities for offering or sale in any jurisdiction, or the
initiation of any proceeding for any of the preceding purposes, and (iv) of the
existence of any fact or the happening of any event that makes any statement of
a material fact made in the registration statement, the prospectus, any
amendment or supplement thereto, or any document incorporated by reference
therein untrue, or that requires the making of any additions to or changes in
the registration statement or the prospectus in order to make the statements
therein not misleading. If at any time the Commission shall issue any stop order
suspending the effectiveness of the registration statement or any state
securities commission or other regulatory authority shall issue an order
suspending the qualification or exemption from qualification of the Registrable
Securities under state securities or blue sky laws, the Company shall use
commercially reasonable efforts to obtain the withdrawal or lifting of such
order at the earliest possible time;

                  (d) furnish to the selling Purchaser and each of the
underwriter(s), if any, before filing with the Commission, copies of the
registration statement or any prospectus included therein or any amendments or
supplements to any such registration statement or prospectus, and the Company
will not file the registration statement or prospectus or any amendment or
supplement to any registration statement or prospectus to which the selling
Purchaser of Registrable Securities covered by such registration statement or
the underwriter(s), if any, shall reasonably object within three (3) business
days after the receipt thereof;



                                       3

<PAGE>   4

                  (e) if requested by the selling Purchaser or the
underwriter(s), if any, incorporate in the registration statement or prospectus,
pursuant to a supplement or post-effective amendment if necessary, such
information as such selling Purchaser and underwriter(s), if any, may reasonably
request to have included therein, information with respect to the number of
Registrable Securities being sold to such underwriter(s), the purchase price
being paid therefor and any other terms of the offering of the Registrable
Securities to be sold in such offering and make all required filings of such
prospectus supplement or post-effective amendment as soon as practicable after
the Company is notified of the matters to be incorporated in such prospectus
supplement or post-effective amendment;

                  (f) furnish to the selling Purchaser and each of the
underwriter(s), if any, without charge, at least one copy of the registration
statement, as first filed with the Commission, and of each amendment thereto,
including all documents incorporated by reference therein and all exhibits
(including exhibits incorporated therein by reference);

                  (g) deliver to the selling Purchaser and each of the
underwriter(s), if any, without charge, as many copies of the prospectus
(including each preliminary prospectus) and any amendment or supplement thereto
as such Persons reasonably may request; the Company hereby consents to the use
of the prospectus and any amendment or supplement thereto by the selling
Purchaser and each of the underwriter(s), if any, in connection with the
offering and the sale of the Registrable Securities covered by the prospectus or
any amendment or supplement thereto;

                  (h) prior to any public offering of Registrable Securities,
the Company shall register or qualify the Registrable Securities under the
securities or blue sky laws of such jurisdictions as the selling Purchaser or
underwriter(s), if any, may reasonably request and do any and all other acts or
things reasonably necessary or advisable to enable the disposition in such
jurisdictions of the Registrable Securities covered by the registration
statement; provided, however, that the Company shall not be required to register
or qualify as a foreign corporation where it is not now so qualified or to take
any action that would subject it to the service of process in suits or to
taxation, other than as to matters and transactions relating to the registration
statement, in any jurisdiction where it is not now so subject;

                  (i) cooperate with the selling Purchaser and the
underwriter(s), if any, to facilitate the timely preparation and delivery of
certificates representing Registrable Securities to be sold and not bearing any
restrictive legends; and enable such Registrable Securities to be in such
denominations and registered in such names as the selling Purchaser or the
underwriter(s), if any, may reasonably request prior to any sale of Registrable
Securities made by such underwriter(s);

                  (j) if any fact or event contemplated by clause (c)(iv) above
shall exist or have occurred, prepare a supplement or post-effective amendment
to the registration statement or related prospectus or any document incorporated
therein by reference or file any other required document so that, as thereafter
delivered to the purchasers of Registrable Securities, the prospectus will not
contain an untrue statement of a material fact or omit to state any material
fact necessary to make the statements therein not misleading;


                                       4

<PAGE>   5

                  (k) cooperate and assist in any filings required to be made
with the National Association of Securities Dealers, Inc. ("NASD") and in the
performance of any due diligence investigation by any underwriter (including any
"qualified independent underwriter") that is required to be retained in
accordance with the rules and regulations of the NASD;

                  (l) otherwise use its commercially reasonable efforts to
comply with all applicable rules and regulations of the Commission, and make
generally available to its security holders, as soon as practicable, a
consolidated earnings statement meeting the requirements of the Securities Act
and Rule 158 thereunder (which need not be audited) for the twelve-month period
(i) commencing at the end of any fiscal quarter in which Registrable Securities
are sold to underwriters in a firm or best efforts underwritten offering or (ii)
if not sold to underwriters in such an offering, beginning with the first month
of the Company's first fiscal quarter commencing after the effective date of the
registration statement;

                  (m) enter into such customary agreements (including an
underwriting agreement in customary form with provisions as may be reasonably
required by the managing underwriter, if any, in order to expedite or facilitate
the disposition of such Registrable Securities);

                  (n) make available for inspection by the selling Purchaser of
Registrable Securities included in such registration statement, any underwriter
participating in any disposition pursuant to such registration statement, and
any attorney, accountant or other agent retained by any such seller or
underwriter (collectively, the "Inspectors"), all relevant financial and other
records, pertinent corporate documents and properties of the Company
(collectively, the "Records"), as shall be reasonably necessary to enable them
to exercise their due diligence responsibility, and cause the Company's
officers, directors and employees to supply all information reasonably requested
by any such Inspector in connection with such registration statement; provided
that Records which the Company determines, in good faith, to be confidential and
which it notifies the Inspectors are confidential shall not be disclosed by the
Inspectors unless (i) the disclosure of such Records is necessary to avoid or
correct a material misstatement or omission in the registration statement or
(ii) the release of such Records is ordered pursuant to a subpoena or other
order from a court of competent jurisdiction; provided, further, each Holder of
Registrable Securities and Inspector agrees that it will, upon learning that
disclosure of such Records is sought in a court of competent jurisdiction, give
notice to the Company and allow the Company, at its expense, to undertake
appropriate action and to prevent disclosure of the Records deemed confidential;

                  (o) obtain a cold comfort letter from the Company's
independent public accountants in customary form and covering such matters of
the type customarily covered by cold comfort letters as the selling Purchaser
may reasonably request; and

                  (p) the Company will give the selling Purchaser of Registrable
Securities registered under such registration statement, the underwriter, if
any, and one counsel or firm of counsel and one accountant or firm of
accountants representing the selling Purchaser, the opportunity to participate
in the preparation of such registration statement, each prospectus included
therein or filed with the Commission, and each amendment thereof or supplement
thereto, and will give each of them such access to its books and records and
such opportunities to


                                       5

<PAGE>   6

discuss the business of the Company with its officers and the independent public
accountants who have certified its financial statements as shall be necessary in
the opinion of such selling Purchaser's and such underwriters' respective
counsel to conduct a reasonable investigation within the meaning of the
Securities Act.

         4. LIMITATIONS ON REQUIRED REGISTRATIONS.

                  (a) The Company shall not be required to effect more than one
registration pursuant to Section 2 hereof.

                  (b) The Company may not cause any other registration of
Securities for sale for its own account (other than a registration effected
solely to implement an employee benefit or incentive plan or securities for a
transaction on a Form S-4) to be initiated after a registration requested
pursuant to Section 2 hereof and to become effective less than ninety (90) days
after the effective date of any registration requested pursuant to Section 2
hereof.

                  (c) Whenever a requested registration is for an underwritten
offering, only shares which are to be included in the underwriting pursuant to
this Agreement or other agreements with the Company, or shares offered by the
Company may be included in the registration. Notwithstanding the provisions of
Sections 2(b) and 4(b) hereof, if the underwriter determines that (i) marketing
factors require a limitation of the total number of shares to be underwritten,
or (ii) the offering price per share would be reduced by the inclusion of the
shares in the underwriting, then the number of shares to be included in the
registration and underwriting shall be reduced in whole or in part by the
underwriter so long as such limitation is applied on a pro rata basis with
respect to all shares proposed or requested to be registered in the
underwriting. No stock excluded from the underwriting by reason of the
underwriter's marketing limitation shall be included in such registration. If
the Company disapproves of any such underwriting, the Company may elect to
withdraw its shares therefrom by written notice to the Purchaser and the
underwriter. The securities so withdrawn from such underwriting shall also be
withdrawn from such registration.

                  (d) If at the time of any request to register Registrable
Securities pursuant to Section 2 hereof, the Company is engaged, or has fixed
plans to engage within ninety (90) days of the time of the request in a
registered public offering, then the Company may at its option direct that such
request be delayed for a period not in excess of six months from the effective
date of such offering.

                  (e) The Company shall not be required to effect a registration
pursuant to Section 2 hereof until the earlier to occur of: (i) 18 months after
an Initial Public Offering if the Company obtains the requisite approval of the
holders of the Preferred Stock for such registration, or (ii) ninety (90) days
after a public offering for the account of the holders of Common Stock issued or
issuable to such holders of the Company's Preferred Stock (the "Preferred
Offering"). If a Preferred Offering has not occurred within 18 months after an
Initial Public Offering, the Company agrees to use its best efforts to obtain
the consent referred to in clause (i) in the previous sentence.


                                       6

<PAGE>   7

         5. INCIDENTAL REGISTRATION. At any time, (i) commencing one hundred
eighty (180) days after an Approved Offering (as defined in the Preferred Rights
Agreement) or (ii) subject to the Preferred Rights Agreement, if the Company
proposes to register any of its shares of Common Stock under the Securities Act
(other than a registration effected solely to implement an employee benefit or
incentive plan or securities for a transaction on a Form S-4) for its own
account or in a Preferred Offering, it will each such time give written notice
to Purchaser of its intention so to do. Upon the written request of Purchaser
given within 10 days after receipt of any such notice (stating the number of
shares of Registrable Securities to be disposed of by Purchaser), the Company
will use commercially reasonable efforts to cause all shares of Registrable
Securities to be sold to be registered under the Securities Act so as to permit
the disposition on the same terms and conditions as the shares of Common Stock
otherwise being sold through underwriters under such registration by such
holders of the shares so registered, subject, however, to the limitations set
forth in the Preferred Rights Agreement and Section 6 hereof.

         6. LIMITATIONS ON INCIDENTAL REGISTRATION. Notwithstanding any
provision of Section 5 hereof, if the underwriter determines that marketing
factors require a limitation of the number of shares to be underwritten, the
underwriter may exclude or otherwise limit the number of shares of Registrable
Securities to be included in the registration and underwriting. The Company
shall so advise the Purchaser, and the number of shares of Registrable
Securities that may be included in the registration and underwriting shall be
reduced in whole or in part by the underwriter. No Registrable Securities
excluded from the underwriting by reason of the underwriter's marketing
limitation shall be included in such registration. If Purchaser disapproves of
any such underwriting, such Purchaser may elect to withdraw therefrom by written
notice to the Company and the underwriter. The Registrable Securities and/or
other securities so withdrawn from such underwriting shall also be withdrawn
from such registration.

         7. DESIGNATION OF UNDERWRITER. The Company shall have the right to
designate the managing underwriter in any underwritten offering.

         8. COOPERATION BY PURCHASER.

                  (a) Purchaser will furnish to the Company such information as
the Company may reasonably require from Purchaser in connection with the
registration statement (and the prospectus included therein).

                  (b) Purchaser will not (until further notice) effect sales
thereof after receipt of telegraphic or written notice form the Company to
suspend sales to permit the Company to correct or update a registration
statement or prospectus; but the obligations of the Company with respect to
maintaining any registration statement current and effective shall be extended
by a period of days equal to the period such suspension is in effect unless (i)
such extension would result in the Company's inability to use the financial
statements in the registration statement initially filed pursuant to the
Purchaser's request and (ii) such correction or update did not result from the
Company's acts or failures to act. At the end of the period during which the
Company is obligated to keep the registration statement current and effective as
described in Section 3(b) hereof (and any extensions thereof required by the
preceding sentence), Purchaser shall discontinue sales of shares pursuant to
such registration statement upon receipt of notice from the


                                       7

<PAGE>   8

Company of its intention to remove from registration the shares covered by such
registration statement which remain unsold, and Purchaser shall notify the
Company of the number of shares registered which remain unsold immediately upon
receipt of such notice from the Company.

                  (c) Purchaser agrees to provide the Company with written
assurances that all sales of Registrable Securities made in connection with a
registration that is not underwritten were made in compliance with all
applicable securities laws, including, without limitation, the prospectus
delivery requirements of Section 5 of the Securities Act or any successor
provision and the restrictions of Rules 10b-2, 10b-6 and 10b-7 of the Exchange
Act or any successor provisions.

         9. EXPENSES OF REGISTRATION. All expenses incurred in effecting any
registration pursuant to this Agreement including, without limitation, all
registration and filing fees, printing expenses, expenses of compliance with
blue sky laws, fees and disbursements of counsel for the Company and expenses of
certified independent public accountants of the Company, shall be borne by the
Company, except that (a) all expenses, fees and disbursements of any counsel
retained by Purchaser and all underwriting discounts and commissions
attributable to Registrable Securities being sold by Purchaser shall be borne by
Purchaser and (b) the Company shall not be required to pay for any expenses of
the registration proceeding begun pursuant to Section 2 hereof if such
registration request is subsequently withdrawn at the request of Purchaser,
unless Purchaser agrees to forfeit its rights to a demand registration pursuant
to Section 2 hereof. Notwithstanding the foregoing, in the case of the
registration requests in which the Company has agreed to pay the Purchasers'
expenses pursuant to this Section 9, the Company will pay up to $10,000 per
registration request, for expenses, fees and disbursements for legal counsel for
the Purchaser.

         10. INDEMNIFICATION.

                  (a) To the extent permitted by law, the Company will indemnify
the Purchaser requesting or joining in a registration, each agent, officer,
member and partner and director of such Purchaser, each Person controlling
(within the meaning of Section 15 of the Securities Act or any successor
provision) such Purchaser and each underwriter and selling broker of the
securities so registered (collectively, "Indemnitees") against all claims,
losses, damages and liabilities (or actions in respect thereof) arising out of
or based on any untrue statement (or alleged untrue statement) of a material
fact contained in any prospectus, offering circular or other document incident
to any registration, qualification or compliance (or in any related registration
statement, notification or the like) or 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 in the light of the circumstances in which
they were made, or any violation by the Company of any rule or regulation
promulgated under the Securities Act applicable to the Company and relating to
action or inaction required of the Company in connection with any such
registration, qualification or compliance, and will reimburse each such
Indemnitee for any legal and any other expenses reasonably incurred in
connection with investigating or defending any such claim, loss, damage,
liability or action; provided, however, that the Company will not be liable in
any such case to the extent that any such claim, loss, damage or liability is
caused by any untrue statement or alleged untrue statement or omission or
alleged omission so made in conformity with written information furnished to the
Company by an instrument duly executed


                                       8

<PAGE>   9


by such Indemnitees and stated to be specifically for use therein and except
that the foregoing indemnity agreement is subject to the condition that, insofar
as it relates to any such untrue statement (or alleged untrue statement) or
omission (or alleged omission) made in the preliminary prospectus but eliminated
or remedied in the amended prospectus on file with the Commission at the time
the registration statement becomes effective or in the amended prospectus filed
with the Commission pursuant to Rule 424(b) or any successor provision (the
"Final Prospectus"), such indemnity agreement shall not inure to the benefit of
any underwriter, or any Indemnitee if there is no underwriter, if a copy of the
Final Prospectus was not furnished to the person or entity asserting the loss,
liability, claim or damage at or prior to the time such furnishing is required
by the Securities Act, provided further, that this indemnity shall not be deemed
to relieve any underwriter of any of its due diligence obligations; provided,
further, that the indemnity agreement contained in this Section 10(a) shall not
apply to amounts paid in settlement of any such claim, loss, damage, liability
or action if such settlement is effected without the consent of the Company,
which consent shall not be unreasonably withheld.

                  (b) To the extent permitted by law, each Purchaser requesting
or joining in a registration and each underwriter of the securities so
registered will indemnify the Company and its officers and directors and each
person, if any, who controls the Company within the meaning of Section 15 of the
Securities Act or any successor provision and their respective successors
against all claims, losses, damages and liabilities (or actions in respect
thereof) arising out of or based on any untrue statement of a material fact
contained in any prospectus, offering circular or other document incident to any
registration, qualification or compliance (or in any related registration
statement, notification or the like) or any omission to state therein a material
fact required to be stated therein or necessary to make the statements therein
not misleading in the light of the circumstances in which they were made and
will reimburse the Company and each other person indemnified pursuant to this
Section 10(b) for any legal and any other expenses reasonably incurred in
connection with investigating or defending any such claim, loss, damage,
liability or action; provided, however, that this Section 10(b) shall apply only
if (and only to the extent that) such statement or omission was made in reliance
upon and in conformity with written information (including, without limitation,
written negative responses to inquiries) furnished to the Company by an
instrument duly executed by such Holder or underwriter and stated to be
specifically for use in such prospectus, offering circular or other document (or
related registration statement, notification or the like) or any amendment or
supplement thereto provided that the indemnity agreement contained in this
Section 10(b) shall not apply to amounts paid in settlement of any such claim,
loss, damage, liability or action if such settlement is effected without the
consent of the Purchaser or underwriter, as the case may be, which consent shall
not be unreasonably withheld.

                  (c) Each party entitled to indemnification hereunder (the
"indemnified party") shall give notice to the party required to provide
indemnification (the "indemnifying party") promptly after such indemnified party
has actual knowledge of any claim as to which indemnity may be sought, and shall
permit the indemnifying party (at its expense) to assume the defense of any
claim or any litigation resulting therefrom, provided that counsel for the
indemnifying party, who shall conduct the defense of such claim or litigation,
shall be reasonably satisfactory to the indemnified party, and the indemnified
party may participate in such defense at such party's expense, and provided
further that the omission by any indemnified party to give notice as provided
herein shall not relieve the indemnifying party of its obligations under this
Section 10


                                       9

<PAGE>   10

except to the extent that the omission results in a failure of actual notice to
the indemnifying party and such indemnifying party is damaged solely as a result
of the failure to give notice. No indemnifying party, in the defense of any such
claim or litigation, shall, except with the consent of each indemnified party,
consent to entry of any judgment or enter into any settlement which does not
include as an unconditional term thereof the giving by the claimant or plaintiff
to such indemnified party of a release from all liability in respect to such
claim or litigation.

                  (d) If for any reason the indemnification provided for in the
preceding subsections (a) and (b) of this Section 10 is unavailable to an
indemnified party or insufficient to hold it harmless as contemplated by such
preceding subsections, then the indemnifying party shall contribute to the
amount paid or payable by the indemnified party as a result of such
unavailability or insufficiency in proportion as is appropriate to reflect not
only the relative benefits received by the indemnified party and the
indemnifying party, but also the relative fault of the indemnified party and the
indemnifying party, as well as any other relevant equitable considerations,
provided that Purchaser shall not be required to contribute in any amount
greater than the dollar amount of the proceeds received by Purchaser with
respect to the sale of any Common Stock. 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.

                  (e) The reimbursement required by this Section 10 shall be
made by periodic payments during the course of the investigation or defense, as
and when bills are received or expenses incurred.

                  (f) The obligation of the Company under this Section 10 shall
survive the completion of any offering of Registrable Securities in a
registration statement under this Agreement, or otherwise.

         11. RIGHTS WHICH MAY BE GRANTED TO SUBSEQUENT INVESTORS. The Company
may grant to subsequent investors in the Company rights of incidental
registration (such as those provided in Section 2 and 5 hereof). Such rights may
be granted with respect to (i) registrations actually requested by Purchaser
pursuant to Section 2 hereof, but only in respect of that portion of any such
registration as remains after inclusion of all Registrable Securities requested
by Purchaser and (ii) registrations initiated by the Company.

         12. ASSIGNMENT OF REGISTRATION RIGHTS. Except as otherwise provided
below, neither party may assign any of its rights and obligations of the parties
hereunder without the prior written consent of the other party:

                  (a) Purchaser may assign this Agreement and all its rights and
obligations to a transferee who executes a counterpart of this Agreement and
agrees to be bound by the agreements, representations and warranties herein and
such permitted transferee shall be substituted for Purchaser in the Agreement;
but only to a transferee who shall acquire the Warrant or all shares of
Registrable Securities initially issuable under the Warrant and in compliance
with applicable securities laws and the terms of the Warrant; or


                                       10


<PAGE>   11

                  (b) either party may assign this Agreement and all its rights
and obligations under this Agreement to the assignee of all or substantially all
of the assets of such party including an acquisition through merger, provided
that such party shall in no event be released from its obligations hereunder
without the prior written consent of the other party.

         Notwithstanding any provision of this Section 12, the registration
rights granted to the Purchaser under this Agreement may not be assigned to any
Person which, in the Company's reasonable judgment, is a competitor of the
Company.

         13. "STAND-OFF" AGREEMENT. In consideration for the Company performing
its obligations under this Agreement, Purchaser agrees to enter into an
agreement providing that for a period of time (not to exceed one hundred eighty
(180) days) from the effective date of any registration (other than a
registration effected solely to implement an employee benefit or incentive plan)
of Common Stock (or derivatives thereof) of the Company (upon request of the
Company or of the underwriters managing the underwritten offering covered by
such registration), such Purchaser shall not sell, make any short sale of, loan,
grant any option for the purchase of, or otherwise dispose of any Registrable
Securities, other than shares of Registrable Securities included in the
registration, without the prior written consent of the Company or such
underwriters, as the case may be; provided, however, such Purchaser shall not be
obligated to enter into such agreement unless all executive officers and
directors of the Company shall have entered into similar agreements.

         14. DELAY OF REGISTRATION. The Purchaser shall have no right to take
any action to restrain, enjoin, or otherwise delay any registration as the
result of any controversy that might arise with respect to the interpretation or
implementation of this Agreement.

         15. TERMINATION OF REGISTRATION RIGHTS. Unless the registration rights
granted in this Agreement are terminated earlier, the registration rights shall
terminate on the earlier of:

                  (a) June 2, 2006; or

                  (b) with respect to Purchaser, or permissible transferee or
assignee of such rights, at such time when such Purchaser or transferee or
assignee owns less than the number of shares of Registrable Securities that
could be sold within a single three-month period pursuant to Rule 144.

         16. RULE 144 REQUIREMENTS. If the Company becomes subject to the
reporting requirements of the Exchange Act, the Company will file with the
Commission such information as the Commission may require to make available Rule
144 under the Securities Act (or any successor exemptive rule).

         17. NOTICES. All notices, requests, consents and other communications
herein (except as stated in the last sentence of this Section 17) shall be in
writing and shall be mailed by first class or certified mail, postage prepaid,
sent by a nationally recognized overnight delivery service, or personally
delivered, as follows:



                                       11


<PAGE>   12

                    (a)    If to the Company:

                           BroadbandNOW, Inc.
                           1440 Corporate Drive
                           Irving, Texas  75038
                           Attn:  Matthew Hutchins, Sr., President and CEO

                           with a copy which shall not constitute notice to:

                           King & Spalding
                           1185 Avenue of the Americas
                           New York, New York  10036-4003
                           Attn:  Mark Zvonkovic

                    (b)    If to the Purchaser:

                           Marcus & Partners, L.P.
                           300 Crescent Court
                           Suite 800
                           Dallas, Texas  75201
                           Attn:  Jeffrey A. Marcus

                           with a copy which shall not constitute notice to:

                           Weil Gotshal & Manges LLP
                           100 Crescent Court
                           Suite 1300
                           Dallas, Texas  75201
                           Attn:  Michael A. Saslaw

or such other addresses as each of the parties hereto may provide from time to
time in writing to the other parties.

         18. MODIFICATIONS; WAIVER. Neither this Agreement nor any provision
hereof may be changed, waived, discharged or terminated orally or in writing,
except that any provision of this Agreement may be amended and the observance of
any such provision may be waived (either generally or in a particular instance
and either retroactively or prospectively) with (but only with) the written
consent of (a) the Company and (b) Purchaser.

         19. REPLACEMENT AGREEMENT. This Agreement contains the entire agreement
between the parties with respect to the registration rights contemplated hereby,
and supersede all negotiations, agreements, representations, warranties and
commitments relating to the registration rights contemplated hereby, whether in
writing or oral, prior to the date hereof.

         20. SUCCESSORS AND ASSIGNS. The Company may not assign or delegate any
of its rights or duties under this Agreement. Except as otherwise provided in
this Agreement, all of the terms of this Agreement including the agreements,
representations and warranties set forth herein shall be binding upon and inure
to the benefit of and be enforceable by the respective successors



                                       12

<PAGE>   13

and assigns of the parties hereto, except that the rights set forth in this
Agreement may only be transferred in accordance with Section 12 hereof.

         21. ENFORCEMENT.

                  (a) Remedies at Law or in Equity. If any party shall default
in any of its obligations under this Agreement or if any representation or
warranty made by or on behalf of such party in this Agreement or in any
certificate, report or other instrument delivered under or pursuant to any term
hereof shall be untrue or misleading in any material respect as of the date of
this Agreement or as of the date it was made, furnished or delivered, any party
damaged may proceed to protect and enforce its rights by suit in equity or
action at law, whether for the specific performance of any term contained in
this Agreement or for an injunction against the breach of any such term or in
furtherance of the exercise of any power granted in this Agreement, or to
enforce any other legal or equitable right of such party or to take any one or
more of such actions. The prevailing party in such dispute shall be entitled to
recover from the losing party all fees, costs and expenses of enforcing any
right of such prevailing party under or with respect to this Agreement,
including without limitation reasonable fees and expenses of attorneys and
accountants, which shall include, without limitation, all fees, costs and
expenses of appeals.

                  (b) Remedies Cumulative; Waiver. No remedy referred to herein
is intended to be exclusive, but each shall be cumulative and in addition to any
other remedy referred to above or otherwise available at law or in equity. No
express or implied waiver of any default shall be a waiver of any future or
subsequent default. The failure or delay in exercising any rights granted
hereunder shall not constitute a waiver of any such right and any single or
partial exercise of any particular right shall not exhaust the same or
constitute a waiver of any other right provided herein.

         22. EXECUTION AND COUNTERPARTS. This Agreement may be executed in any
number of counterparts, each of which when so executed and delivered shall be
deemed an original, and such counterparts together shall constitute one
instrument. Each party shall receive a duplicate original of the counterpart
copy or copies executed by it and by the Company.

         23. GOVERNING LAW AND SEVERABILITY. THIS AGREEMENT SHALL BE GOVERNED BY
THE LAWS OF THE STATE OF TEXAS AS APPLIED TO AGREEMENTS ENTERED INTO AND TO BE
PERFORMED ENTIRELY WITHIN TEXAS. To the maximum extent practicable, this
Agreement will be deemed to call for performance in Dallas County, Texas. In the
event any provision of this Agreement or the application of any such provision
to any party shall be held by a court of competent jurisdiction to be contrary
to law, the remaining provisions of this Agreement shall remain in full force
and effect.

         24. HEADINGS. The descriptive headings of the Sections hereof and the
Schedules hereto are inserted for convenience only and do not constitute a part
of this Agreement.



                                       13

<PAGE>   14



                  IN WITNESS WHEREOF, the parties hereto have duly executed this
Agreement as of the day and year first above written.

                               MARCUS & PARTNERS, L.P.

                               By:  Marcus & Partners Holdings, L.L.C.



                                    By:
                                       -------------------------------------
                                         Name:  Jeffrey A. Marcus
                                         Title:  Manager


                               BROADBANDNOW, INC.



                               By:
                                  ------------------------------------------
                                    Name:  Matthew Hutchins
                                    Title:  President