<PAGE>

                                                                    Exhibit 10.8










                              GIGABEAM CORPORATION

                       NOTE AND WARRANT PURCHASE AGREEMENT

                          DATED AS OF JANUARY 26, 2004


<PAGE>



                       NOTE AND WARRANT PURCHASE AGREEMENT

         This NOTE AND WARRANT PURCHASE AGREEMENT (this "Agreement") dated
January 26, 2004 is by and between GIGABEAM CORPORATION, a Delaware corporation
(the "Company"), and the purchaser enumerated on Schedule I attached hereto
("Purchaser").

         In consideration of the premises and the covenants hereinafter
contained, and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, hereby agree as follows:

                                   ARTICLE I
                  PURCHASE, SALE AND TERMS OF NOTE AND WARRANT

         Section 1.1 The Notes. The Company has authorized the issuance and sale
to the Purchaser of a convertible demand note (the "Note"), in the aggregate
principal amount of up to One Million Dollars ($1,000,000.00). The Note shall be
substantially in the form set forth in Exhibit A hereto.

         Section 1.2 The Warrants. The Company has also authorized the issuance
and sale to the Purchaser of a warrant (the "Warrant") to purchase the Company's
Preferred Stock; the shares subject to the Warrant shall constitute authorized
but unissued shares and shall be subject to adjustment in accordance with the
terms of the Warrants. The Warrant shall be substantially in the form set forth
in Exhibit B hereto.

         Section 1.3 Purchase and Sale of Note and Warrant.

                     (a) The Closing. The Company agrees to issue and sell to
the Purchaser, and, subject to and in reliance upon the representations,
warranties, terms and conditions of this Agreement, the Purchaser agrees to
purchase from the Company, a Note and a Warrant for the aggregate purchase price
set forth opposite the Purchaser's name on Schedule I. Such purchase and sale
shall take place at a closing (the "Closing") to be held at the offices of
Seyfarth Shaw, World Trade Center East, Suite 300, Boston, Massachusetts 02210
on January ___, 2004 at 9:00 A.M. (the "Closing Date"), or on such other date
and at such other time as may be mutually agreed upon. At the Closing, the
Company will issue a Note, dated the Closing Date, payable to the order of each
of the Purchaser, in the principal amount set forth opposite the Purchaser's
name on Schedule I (the "Principal Amount"), and will issue a Warrant to each of
the Purchasers, against receipt by the Company of a wire transfer in payment of
the full Principal Amount by the Purchaser at the Closing.

                     (b) Allocation of Purchase Price. The Company and the
Purchaser, having adverse interests and as a result of arm's length bargaining,
agree that: (i) neither the Purchaser nor any of its affiliates has rendered or
has agreed to render any services to the Company in connection with this
Agreement or the issuance of the Note and the Warrant; and (ii) the Warrant,
when issued, shall not be issued as compensation. The Company and the Purchasers
agree that the fair market value of each of the Purchaser's right hereunder to
be issued a Warrant is equal to one percent (1%) of the Principal Amount.


<PAGE>

                     (c) Use of Proceeds. The Company agrees to use the proceeds
from the sale of the Note and the Warrant for general working capital purposes.

         Section 1.4 Payments and Endorsements. Payments of principal, interest
and premium, if any, on the Note shall be made directly by wire transfer or by
check duly mailed or delivered to the Purchaser at the address enumerated on
Schedule I hereto, without any presentment or notation of payment, except that
prior to any transfer of the Note, the holder of record shall endorse on the
Note a record of the date to which interest has been paid and all payments made
on account of principal of the Note.

         Section 1.5 Payment on Non-Business Days. Whenever any payment to be
made shall be due on a day which is not a Business Day (as hereinafter defined),
such payment may be made on the next succeeding Business Day, and such extension
of time shall in such case be included in the computation of payment of interest
due.

         Section 1.6 Registration, etc. The Company shall maintain at its
principal office a register relating to the Note and shall record therein the
names and addresses of the registered holders of the Note, the address to which
notices are to be sent and the address to which payments are to be made as
designated by the registered holder if other than the address of the holder, and
the particulars of all transfers, exchanges and replacements of the Notes. No
transfer of the Notes shall be valid unless made on such register for the
registered holder or his, her or its executors or administrators or his, her or
their duly appointed attorney, upon surrender therefor for exchange as
hereinafter provided, accompanied by an instrument in writing, in form and
execution reasonably satisfactory to the Company. The Note or any other note
issued hereunder, whether originally or upon transfer, exchange or replacement
of the Note, shall be registered on the date of execution thereof by the Company
and shall be dated the date to which interest has been paid on such Note. The
registered holder of a Note shall be that Person (as hereinafter defined) in
whose name a Note has been so registered by the Company. A registered holder
shall be deemed the owner of a Note for all purposes of this Agreement and,
subject to the provisions hereof, shall be entitled to the principal, premium,
if any, and interest evidenced by such Note free from all equities or rights of
set-off or counterclaim among the Company and the transferor of such registered
holder or any previous registered holder of the Note.

         Section 1.7 Transfer and Exchange of Note. Subject to compliance with
all applicable state and federal securities laws, the registered holder of the
Note may, prior to the acceleration or prepayment thereof, surrender the Note at
the principal office of the Company for transfer or exchange. Within a
reasonable time after notice to the Company from a registered holder of its
intention to make such exchange and without expense (other than transfer taxes,
if any) to such registered holder, the Company shall, at its cost and expense,
issue in exchange therefor another note or notes, in such denominations as
requested by the registered holder, for the same aggregate principal amount as
the unpaid principal amount of the note or notes so surrendered and having the
same maturity and rate of interest, containing the same provisions and subject
to the same terms and conditions as the note or notes so surrendered. Each new
note shall be made payable to such Person or Persons, or registered assigns, as
the registered holder of such surrendered note or notes may designate, and such
transfer or exchange shall be made in such a manner that no gain or loss of
principal or interest shall result therefrom.


                                       2
<PAGE>

         Section 1.8 Replacement of Notes. Upon receipt of evidence satisfactory
to the Company of the loss, theft, destruction or mutilation of a Note or any
note issued in exchange therefor and, if requested in the case of any such loss,
theft or destruction, upon delivery of an indemnity bond or other agreement or
security reasonably satisfactory to the Company, or, in the case of any such
mutilation, upon surrender and cancellation of such note, the Company will issue
a new note, of like tenor and amount and dated the date to which interest has
been paid, in lieu of such lost, stolen, destroyed or mutilated note; provided,
however, if any note of which a Purchaser, its nominee, or any of its partners
or affiliates is the registered holder is lost, stolen or destroyed, the
affidavit of the registered holder setting forth the circumstances with respect
to such loss, theft or destruction shall be accepted as satisfactory evidence
thereof, and no indemnification bond or other security shall be required as a
condition to the execution and delivery by the Company of a new note in
replacement of such lost, stolen or destroyed note other than the registered
holder's written agreement to indemnify the Company.

         Section 1.9 Representations by the Purchaser. The Purchaser hereby
represents as follows:

                     (a) It is the Purchaser's present intention to acquire the
Note and the Warrant for its own account and the Note and the Warrant are being
and will be acquired for the purpose of investment and not with a view to
distribution or resale thereof.

                     (b) The Purchaser is an "accredited investor" within the
meaning of Rule 501 of Regulation D under the Securities Act (as hereinafter
defined) and was not organized for the specific purpose of acquiring the Note
and the Warrant.

                     (c) The Purchaser represents that it has sufficient
knowledge and experience in investing in companies similar to the Company in
terms of the Company's stage of development so as to be able to evaluate the
risks and merits of its investment in the Company and it is able financially to
bear the risks thereof. Purchaser acknowledges that Purchaser has had an
opportunity to make an independent examination of the investment, accounting and
tax aspects of the proposed purchase transaction having relied solely upon the
advice, if any, of Purchaser's counsel, accountants, or business advisors with
regard to the various considerations involved in making an investment in the
Company, and agrees that the Company has no responsibility with respect to such
matters and any such advice. Purchaser further acknowledges that counsel to the
Company does not represent the Purchaser. Purchaser hereby confirms to the
Company that Purchaser has been granted an opportunity to ask questions of and
receive answers from, management of the Company concerning the terms and
conditions of this investment and other matters.

                     (d) The Purchaser has all necessary power and has taken all
action required to make all the provisions of this Agreement, the Note, the
Warrant and any other agreements and instruments executed by it in connection
herewith and therewith the valid and enforceable obligations they purport to be.

                     (e) No Person has or will have, as a result of the
transactions contemplated by this Agreement, any right, interest or valid claim
against or upon the Purchaser for any commission, fee or other compensation as a
finder or broker because of any act or omission by the Purchaser or any agent of
the Purchaser.



                                       3
<PAGE>

         Section 1.10 Conversion of Note. Subject to the terms and provisions of
this Agreement and the Note, upon the closing of a subsequent financing round
(the "Financing Round") yielding gross proceeds to the Company of at least
$2,000,000 (calculated without giving effect to the conversion of the Note) all
of the unpaid principal amount of the Note, together with any accumulated but
unpaid interest thereon accruing, shall be automatically converted into shares
of the Company's preferred securities ("New Securities") issued in connection
with a Financing Round at a conversion price which is the same price per share
as paid by the investors in the Financing Round and upon substantially the same
terms and with such other rights as are granted to investors in the Proposed
Financing Round investing sums substantially equivalent to those of the
Investors, including, without limitation, registration rights where applicable,
provided that the Company, in its sole discretion, may enter into other
agreements providing certain lead investors in the Proposed Financing Round with
rights and benefits more advantageous than those granted to the Investors,
including but not limited to observation rights.

                                   ARTICLE II
                      CONDITIONS TO PURCHASER'S OBLIGATIONS

         Section 2.1 Conditions Precedent. The obligation of the Purchasers to
purchase and pay for the Note and the Warrant to be purchased by them hereunder
at the Closing is subject to the following conditions:

                     (a) Representations and Warranties. Each of the
representations and warranties of the Company set forth in Article III hereof
shall be true and correct on the date of the Closing Date.

                     (b) Documentation at Closing. The Purchaser shall have
received prior to or at the Closing (i) the duly executed Note and Warrant to be
issued as of such date, and (ii) a certified copy of the resolutions of the
Board of Directors of the Company evidencing approval of this Agreement, the
Note, the Warrant, and the other matters contemplated thereby.

                                  ARTICLE III
                         REPRESENTATIONS AND WARRANTIES

         The Company represents and warrants to the Purchasers, as of the date
hereof and as of the Closing Date, as follows, except as otherwise provided in
the Disclosure Schedules attached hereto:

         Section 3.1 Required Action. Except for the authorization and
designation of the New Securities, the Company has all necessary power and has
taken all action required to make all the provisions of this Agreement, the
Note, the Warrant and any other agreements and instruments executed by it in
connection herewith and therewith the valid and enforceable obligations they
purport to be. Neither the issuance of the Note or the Warrant, the issuance of
Preferred Stock upon exercise of the Warrants, nor the issuance of the Company's
New Securities or Common Stock, as the case may be, upon conversion of the
Notes, is subject to preemptive or other similar statutory or contractual rights
or will conflict with any provisions of any agreement or instrument to which the
Company is a party or by which it is bound.



                                       4
<PAGE>

         Section 3.2 Governmental Approvals. No authorization, consent,
approval, license, or filing or registration with, any court or governmental
department, commission, board, bureau, agency or instrumentality, domestic or
foreign, is or will be necessary for, or in connection with, the offer,
issuance, sale, execution or delivery by the Company of, or for the performance
by it of its obligations under, this Agreement, the Note or the Warrant except
for applicable federal and state securities filings.

         Section 3.3 Compliance with Other Instruments. Neither the execution
and delivery of this Agreement, the Note, the Warrant, nor the consummation of
any transactions contemplated hereby or thereby, has constituted or resulted in
or will constitute or result in a material default or violation of any term or
provision in any instrument, judgment, order, writ, decree or contract to which
the Company is a party or by which it is bound, or, to the best of its
knowledge, of any provision of any federal or state statute, rule or regulation
applicable to the Company's business now or as proposed to be conducted, except
for such defaults or violations that would not have a material adverse effect on
the Company's business or properties.

         Section 3.4 No Brokers or Finders. No Person (other than the Purchaser)
has or will have, as a result of the transactions contemplated by this
Agreement, any right, interest or valid claim against or upon the Company for
any commission, fee or other compensation as a finder or broker because of any
act or omission by the Company or any agent of the Company.

                                   ARTICLE IV
       DEMAND OBLIGATIONS; EVENTS OF DEFAULT; REMEDIES; CHANGE OF CONTROL

         Section 4.1 Demand Obligations; Events of Default. Nothing contained in
this section, or elsewhere in this Agreement, shall affect or alter the demand
nature of such of the Obligations (as hereinafter defined) as are by their
terms, demand obligations. The occurrence of an Event of Default shall not be a
prerequisite for the Purchaser making demand or requiring payment of such
obligations except as set forth in the Note. The Company hereby expressly
acknowledges and agrees that the Events of Default are set forth herein as
examples of some, but not necessarily all, of the events or occurrences that may
cause the Purchaser to make demand for payment of any Obligations that are by
their terms payable on demand, and that the following shall otherwise constitute
Events of Default in respect of any Obligations that are not by their terms (or
that may be interpreted by a court of competent jurisdiction not to be) demand
obligations.

         Subject to the provisions of the first paragraph of this section, the
occurrence of any one or more of the following events shall constitute an event
of default hereunder (said events are hereinafter referred to individually as an
"Event of Default" and together as the "Events of Default"), entitling the
Purchasers to pursue all of its remedies hereunder and under any of the other
Financing Documents (as hereinafter defined):

                     (a) The failure of the Company to pay any amount of
principal and interest under the Note when and as due thereunder within ten (10)
days of the date when due;



                                       5
<PAGE>

                     (b) The termination of existence, dissolution, winding up
or liquidation of the Company or the sale or other transfer of all or
substantially all of the assets or the capital stock of the Company to a third
party; or

                     (c) Any voluntary bankruptcy, reorganization, debt
arrangement, composition or readjustment, liquidation with respect to the
Company or any of its property or the appointment of any receiver, master,
assignee, liquidator, custodian or other similar Person with respect to the
Company or any of its property or any involuntary bankruptcy proceeding which is
not dismissed within ninety (90) days of commencement;

         then, and in any such event, so long as the same may be continuing, the
Purchaser may, subject to Section 1.10 hereof, by notice in writing to the
Company, declare all of the Obligations owed to the Purchaser to be, and they
shall thereupon forthwith become, immediately due and payable without
presentment, demand, protest or other notice of any kind, all of which are
hereby expressly waived by the Company; provided, however, that in the event of
any Event of Default specified in clauses (c) and (d) of this Section 5.1, all
of the Obligations shall become immediately due and payable automatically and
without any requirement of notice from the Purchaser.

         Section 4.2 General Remedies. In addition to and without in any way
limiting any other rights and remedies available to any of the Purchaser
hereunder or under any of the other Financing Documents or under applicable law
or in equity, and at any time or times following the demand for payment of the
Obligations which are payable on demand, and the expiry of any applicable grace
period, or upon the occurrence of an Event of Default:

                     (a) the Purchaser may declare and cause all or any portion
of the Obligations to be immediately due and payable;

                     (b) the Purchasers shall have the right to apply to the
Obligations any deposits or other sums at any time credited by or due from the
Purchaser to the Company; and

                     (c) the Purchasers may exercise any rights and remedies
available under the Financing Documents as they shall deem appropriate.

         Section 4.3 Remedies Not Exclusive. The enumeration of rights and
remedies in the Financing Documents is not intended to be exclusive, and they
shall be in addition to and not by way of limitation of such others as the
Purchasers may have under applicable law, and any and all other documents,
instruments, agreements or other writings between or among Company, the
Purchaser or other Persons. The Purchasers shall determine its choice of rights
and remedies and the order in which they shall be exercised. The exercise of any
right or remedy against the Company or any other Person shall not preclude the
exercise of others or the exercise thereof against Company, any other Person or
any other collateral, all of which shall be cumulative. No act, failure or delay
by the Purchaser shall constitute a waiver of any of their rights and remedies.
No single or partial waiver by the Purchaser of any provision of the Financing
Documents, or of any breach or default thereunder, or of any right or remedy
which the Purchaser may have, shall operate as a waiver of any other provision,
breach, default, right or remedy or of the same one on a future occasion.



                                       6
<PAGE>

         Section 4.4 Change of Control. Notwithstanding any other provision of
this Agreement, the Purchaser shall be entitled to make demand to the Company
for the payment of the Obligations immediately prior to the closing of a Change
of Control. For the purposes of this Agreement, a "Change of Control" shall mean
(A) the acquisition of the Company by another entity by means of any transaction
or series of related transactions (including, without limitation, any
reorganization, merger or consolidation) that results in the transfer of fifty
percent (50%) or more of the outstanding voting power of the Company; or (B) a
sale, transfer, license or lease of all or substantially all of the assets of
the Company..



                                   ARTICLE V
                        DEFINITIONS AND ACCOUNTING TERMS

         Section 5.1 Certain Defined Terms. As used in this Agreement, the
following terms shall have the following meanings (such meanings to be equally
applicable to both the singular and plural forms of the terms defined):

         "Agreement" means this Note and Warrant Purchase Agreement, as from
time to time amended and in effect between the parties.

         "Business Day" means a day other than Saturday, Sunday or a public
holiday under the laws of the State of Delaware.

         "Change of Control" shall have the meaning assigned to that term in
Section 4.4.

         "Closing" shall have the meaning assigned to that term in Section
1.3(a).

         "Closing Date" shall have the meaning assigned to that term in Section
1.3(a).

         "Commission" means the United States Securities and Exchange Commission
or any other federal agency at the time administering the Securities Act.

         "Company" means GigaBeam Corporation, and its successors and assigns.

         "Events of Default" shall have the meaning assigned to that term in
Section 4.1.

         "Exchange Act" means the Securities Exchange Act of 1934 or any similar
federal statute, and the rules and regulations of the Commission (or of any
other Federal Agency then administering the Exchange Act) thereunder, all as the
same shall be in effect at the time.

         "Financing Documents" means and includes the following, as the same may
be hereafter amended, modified, substituted, extended or restated, from time to
time: this Agreement, the Note, the Warrant, and any and all other documents,
instruments, agreements and writings, whether now or hereafter executed by or on
behalf of the Company, and delivered or assigned to the Purchaser in connection
with the transactions contemplated herein or therein.

         "Financing Round" shall have the meaning assigned to that term in
Section 1.10.



                                       7
<PAGE>

         "New Securities" shall have the meaning assigned to that term in
Section 1.10.

         "Notes" shall have the meaning assigned to that term in Section 1.1.

         "Obligations" means any and all indebtedness, liabilities, duties,
undertakings, warranties, covenants and agreements (including those of payment
or performance) of the Company to the Purchaser, of every kind, nature and
description, which arise under or pursuant to the terms of any or all of the
Financing Documents, whether or not the same are now existing or hereafter
arising, due or not due, absolute or contingent, liquidated or unliquidated.

         "Person" means an individual, corporation, partnership, joint venture,
limited liability company, trust, or unincorporated organization, or a
government or any agency or political subdivision thereof, or any other entity
or business form.

         "Principal Amount" shall have the meaning assigned to that term in
Section 1.3(a).

         "Purchaser" means and shall include not only the Persons enumerated on
Schedule I hereto but also any other permitted transferees of the Note or the
Warrant.

         "Securities Act" means the Securities Act of 1933 or any similar
federal statute, and the rules and regulations of the Commission (or of any
other federal agency then administering the Securities Act) thereunder, all as
the same shall be in effect at the time.

         "Subsidiary" or "Subsidiaries" means any corporation, association,
joint stock company, business trust or other similar organization of which fifty
percent (50%) or more of the ordinary voting power for the election of a
majority of the members of the board of directors or other governing body of
such entity is held or controlled by the Company; or any other such organization
the management of which is directly or indirectly controlled by the Company
through the exercise of voting power or otherwise.

         "Warrant" shall have the meaning assigned to that term in Section 1.2.

                                   ARTICLE VI
                                  MISCELLANEOUS

         Section 6.1 No Waiver; Cumulative Remedies. No failure or delay on the
part of the Purchaser, or any other holder of the Note and the Warrant in
exercising any right, power or remedy hereunder shall operate as a waiver
thereof, nor shall any single or partial exercise of any such right, power or
remedy preclude any other or further exercise thereof or the exercise of any
other right, power or remedy hereunder. The remedies herein provided are
cumulative and not exclusive of any remedies provided by law.

         Section 6.2 Amendments, Waivers and Consent. Any provision in this
Agreement, the Note or the Warrant to the contrary notwithstanding, changes in
or additions to this Agreement may be made, and compliance with any covenant or
provision herein or therein set forth may be omitted or waived, if the Company
shall obtain consent thereto in writing from the Purchasers. Any waiver or
consent may be given subject to satisfaction of conditions stated therein and
any waiver or consent shall be effective only in the specific instance and for
the specific purpose for which given.



                                       8
<PAGE>

         Section 6.3 Addresses for Notices, etc. All notices, requests, demands
and other communications provided for hereunder shall be in writing (including
telefacsimile communication) and mailed or faxed or delivered to the applicable
party at the addresses indicated below:

If to the Company:                  GigaBeam Corporation
                                    14225-C Sullyfield Circle
                                    138 River Road - 2nd Floor
                                    Chantilly, VA 20151
                                    Attn:  President

         If to the Purchaser, at the address set forth in Schedule I.

         If to any other holder of the Note or the Warrant, at such holder's
address for notice as set forth in the register maintained by the Company, or,
as to each of the foregoing, at such other address as shall be designated by
such Person in a written notice to the other party complying as to delivery with
the terms of this section. All such notices, requests, demands and other
communications shall, when mailed or faxed, respectively, be deemed delivered
three (3) days after deposited in the mails or faxed with transmission confirmed
electronically, respectively, addressed as aforesaid.

         Section 6.4 Costs, Expenses and Taxes. Each party shall bear its own
expenses with respect to the preparation, execution and delivery of this
Agreement, the Note, the Warrant and other instruments and documents to be
delivered hereunder. I

         Section 6.5 Binding Effect; Assignment. This Agreement shall be binding
upon and inure to the benefit of the Company and the Purchaser and their
respective successors and assigns, except that the Company shall not have the
right to assign its rights hereunder or any interest herein without the prior
written consent of the Purchaser.

         Section 6.6 Survival of Representations and Warranties. All
representations and warranties made in this Agreement, the Notes, the Warrants
or any other instrument or document delivered in connection herewith or
therewith, shall survive the execution and delivery hereof or thereof and the
making of the loan.

         Section 6.7 Prior Agreements. This Agreement constitutes the entire
agreement between the parties and supersedes any prior understandings or
agreements concerning the subject matter hereof.

         Section 6.8 Severability. The invalidity or unenforceability of any
provision hereof shall in no way affect the validity or enforceability of any
other provision.

         Section 6.9 Headings. Article, section and subsection headings in this
Agreement are included herein for convenience of reference only and shall not
constitute a part of this Agreement for any other purpose.



                                       9
<PAGE>

         Section 6.10 Counterparts. This Agreement may be executed in any number
of counterparts, all of which taken together shall constitute one and the same
instrument, and each of the parties hereto may execute this Agreement by signing
any such counterpart.

         Section 6.11 Further Assurances. From and after the date of this
Agreement, upon the request of the Purchasers, the Company shall execute and
deliver such instruments, documents and other writings as may be necessary or
desirable to confirm and carry out and to effectuate fully the intent and
purposes of this Agreement, the Note and the Warrant.

         Section 6.12 Governing Law. This Agreement shall be governed by and
construed in accordance with the laws of the State of Delaware for all purposes
and in all respects, without giving effect to the conflict of law provisions
thereof.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]




                                       10
<PAGE>


         IN WITNESS WHEREOF, the undersigned have each duly executed or caused
to be executed this Agreement, under seal, as of the day and year first written
above.



                                    COMPANY:

                                    GIGABEAM CORPORATION


                                    By:  /s/ L. Slaughter
                                         ----------------------------
                                    Name:  L. Slaughter
                                           --------------------------
                                    Title:  CEO
                                            -------------------------


                                   PURCHASER:


                                   AMERISTOCK CORP.

                                   /s/ Nicholas Gerber
                                   -------------------------
                                   Name: /s/ Nicholas Gerber


<PAGE>



                         LIST OF EXHIBITS AND SCHEDULES


Schedule I                 Purchaser

Exhibit A                  Form of Note
Exhibit B                  Form of Warrant

Schedule 3                 Exceptions




<PAGE>



                                   SCHEDULE I

                                    PURCHASER


Name                                                         Principal Amount
----                                                         ----------------

[To be completed]                                            $1,000,000


<PAGE>



                                    EXHIBIT A

                                  FORM OF NOTE

THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE SECURITIES
ACT OF 1933, AS AMENDED, AND MAY NOT BE SOLD, ASSIGNED OR TRANSFERRED WITHOUT AN
EFFECTIVE REGISTRATION STATEMENT FOR SUCH SECURITIES UNDER THE SECURITIES ACT OF
1933, AS AMENDED, UNLESS THE COMPANY HAS RECEIVED THE WRITTEN OPINION OF COUNSEL
SATISFACTORY TO THE COMPANY TO THE EFFECT THAT SUCH SALE, ASSIGNMENT OR TRANSFER
DOES NOT INVOLVE A TRANSACTION REQUIRING REGISTRATION OF SUCH SECURITIES UNDER
THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS.

                             CONVERTIBLE DEMAND NOTE

                                January __, 2004

         For value received, GIGABEAM CORPORATION, a Delaware corporation (the
"Company"), hereby unconditionally promises to pay to the order of _____________
or registered assigns (the "Payee"), ON DEMAND, the principal sum of One Million
Dollars ($1,000,000.00), together with interest thereon, and premium, if any,
all as hereinafter provided, if not earlier converted pursuant to the Agreement
(as hereinafter defined). Such principal sum, together with all interest
incurred thereon, premium (if any), and all other fees and costs, shall be due
and payable ON DEMAND and, except as provided herein, the Payee's right to make
demand is unconditional and unlimited; notwithstanding the foregoing, prior to
the one year anniversary of the date of issuance of this Note (the "Maturity
Date"), the Payee may only make demand (if not earlier converted as provided in
the Agreement): (i) following the occurrence and continuance of an Event of
Default (as such term is defined in the Agreement) or (ii) immediately prior to
the closing of a Change of Control (as such term is defined in the Agreement),
which shall permit the acceleration and demand of this Note.

         The Company agrees that the Payee, in the exercise of the Payee's sole
discretion, may make demand at any time after the Maturity Date whether or not
any Event of Default or Change of Control has occurred and is continuing, and
may make demand at any time either before or after the Maturity Date in the
event of either of the occurrences described in items (i) and (ii) of the
immediately preceding paragraph of this Note. The Company agrees that, in
exercising its discretion, the Payee may make demand for any reasons which it
deems appropriate, and such reasons may be related or unrelated to the Company,
its business or financial condition or prospects. The Payee's right to make
demand is a continuing right, and acceptance by the Payee of any payment after
demand shall not be deemed a waiver of such right to make demand on any other
occasion.

         Prior to the date upon which the balance of this Note becomes due and
payable as described herein, whether by demand or otherwise (the "Payment Due
Date") and after the Payment Due Date, the unpaid principal balance outstanding
on all advances, from time to time, hereunder shall accrue interest at a rate
equal to ten percent (10%) per annum. Interest shall be compounded annually and
shall be computed on the basis of a 360-day year and a 30-day month.
Notwithstanding any other provision of this Note, the Payee does not intend to
charge and the Company shall not be required to pay any interest or other fees
or charges in excess of the maximum permitted by applicable law; any payments in
excess of such maximum shall be refunded to the Company or credited to reduce
principal hereunder. All payments received by the Payee hereunder will be
applied first to costs of collection and fees, if any, then to interest, then to
principal and the balance to premium (if any).


<PAGE>

         All principal plus accrued and unpaid interest on the Note and premium
(if any) shall be immediately due and payable upon notice in writing from Payee
to the Company, without presentment, demand, protest, or notice, upon the
occurrence of an Event of Default of the type specified in Section 4.1 of the
Agreement, after taking account of all applicable grace and cure periods
thereunder. All accrued and unpaid interest on the Note and premium (if any)
shall be paid upon payment of the principal of the Note, whether by demand, or
upon acceleration as provided herein, or otherwise. At the time that the payment
of the balance of this Note becomes due, the Payee may proceed with every remedy
available at law or in equity.

         This Note is issued pursuant to and is entitled to the benefits of a
certain Note and Warrant Purchase Agreement, dated as of January __, 2004, by
and among the Company and the purchaser named therein (the "Agreement"), the
terms of which are incorporated herein, and each holder of this Note, by his,
her or its acceptance hereof, agrees to be bound by the provisions of the
Agreement, including, without limitation, the representations contained in
Section 1.9 thereof. Without limiting the foregoing, the holder of this Note is
subject to the mandatory equity conversion provisions as set forth in Section
1.10 of the Agreement.

         Principal and interest shall be payable in lawful money of the United
States of America, at the address of the Payee set forth in the Agreement or at
such other address as the Payee or any subsequent holder may designate from time
to time to the Company in writing. If any day on which a payment is due pursuant
to the terms of this Note is not a Business Day (as such term is defined in the
Agreement), such payment shall be due on the next Business Day following.

         Upon surrender of this Note for transfer or exchange, a new note or new
notes of the same tenor dated the date to which interest has been paid on the
surrendered Note and in an aggregate principal amount equal to the unpaid
principal amount of the Note so surrendered will be issued to, and registered in
the name of, the transferor or transferees. The Company may treat the person in
whose name this Note is registered as the owner hereof for the purpose of
receiving payment and for all other purposes.

         In the event any one or more of the provisions of this Note shall for
any reason be held to be invalid, illegal or unenforceable, in whole or in part
or in any respect, or in the event that any one or more of the provisions of
this Note operate or would prospectively operate to invalidate this Note, then
and in any such event, such provision(s) only shall be deemed null and void and
shall not affect any other provision of this Note and the remaining provisions
of this Note shall remain operative and in full force and effect and in no way
shall be affected, prejudiced, or disturbed thereby.


<PAGE>

         In case any payment herein provided for shall not be paid when due, the
Company promises to pay all costs of collection or enforcement of this Note,
including, without limitation, court costs and all reasonable attorney's fees
and expenses incurred or paid by the Payee in enforcing the obligations of the
Company.

         This Note may be not be prepaid without the prior written consent of
the Payee.

         All notices to the Company and the Payee required or permitted
hereunder shall be made in accordance with the Agreement.

         This Note shall be governed by, and construed in accordance with, the
laws of the State of Delaware.

         Whenever used herein, the terms "Company" and "Payee" shall be deemed
to include, to the extent applicable, the successors and assigns of such
parties; provided, however, that the obligations of the Company under this Note
may not be assigned without the express written consent of the Payee or any
holder hereof, which consent may be withheld in the sole and absolute discretion
of such Payee or holder.

         The Company and all endorsers of this Note herein waive presentment,
notice of nonpayment, protest and all other demand and notices in connection
with the delivery, acceptance, performance or enforcement of this Note.

         If any part of this Note shall be adjudged invalid, illegal, or
unenforceable, then such partial invalidity, illegality, or unenforceability
shall not cause the remainder of this Note to be or to become invalid, illegal,
or unenforceable. If a provision hereof is held invalid, illegal or
unenforceable in one or more of its applications, the parties hereto agree that
the other provisions shall remain in effect in all valid, legal and enforceable
applications that are severable from the invalid, illegal or unenforceable
application or applications.

         The validity, meaning, enforceability and effect of this Note, and the
rights and liabilities of the parties, shall be determined in accordance with
the laws of the State of Delaware.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]



<PAGE>



         IN WITNESS WHEREOF, the Company has executed this Note as of the date
and year first written above.



                                          GIGABEAM CORPORATION


                                          By:
                                               ---------------------------------
                                          Name:
                                                 -------------------------------
                                          Title:
                                                  ------------------------------





<PAGE>




                                    EXHIBIT B

                                 FORM OF WARRANT
THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE SECURITIES
ACT OF 1933, AS AMENDED, AND MAY NOT BE SOLD, ASSIGNED OR TRANSFERRED WITHOUT AN
EFFECTIVE REGISTRATION STATEMENT FOR SUCH SECURITIES UNDER THE SECURITIES ACT OF
1933, AS AMENDED, UNLESS THE COMPANY HAS RECEIVED THE WRITTEN OPINION OF COUNSEL
SATISFACTORY TO THE COMPANY TO THE EFFECT THAT SUCH SALE, ASSIGNMENT OR TRANSFER
DOES NOT INVOLVE A TRANSACTION REQUIRING REGISTRATION OF SUCH SECURITIES UNDER
THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS.

Warrant No. _____

Issue Date:         January ___, 2004


                              GIGABEAM CORPORATION

                                     WARRANT

         THIS CERTIFIES that, for value received, ____________________________
or registered assigns (the "Holder") is entitled, upon the terms and subject to
the conditions hereinafter set forth, to subscribe for and purchase from
GIGABEAM CORPORATION, a Delaware corporation (the "Company"), 26.667 shares (as
the same may be adjusted from time to time as set forth herein, the "Warrant
Number") of the Company's Common Stock, $0.001 par value per share ("Common
Stock") at the exercise price of $.01 per share (as the same may be adjusted
from time to time as set forth herein, the "Exercise Price").

         1. Exercise Period - The purchase rights represented by this Warrant
are exercisable by the Holder, in whole or in part, at any time from time to
time during the Exercise Period, which shall commence immediately upon the Issue
Date set forth above and shall end at 5:00 p.m. Boston time on the second
anniversary of the Issue Date.

         2. Exercise of Warrant -

                     (a) During the Exercise Period and provided this Warrant
has not been terminated, this Warrant shall be exercised, in whole or in part
and from time to time, by the surrender of this Warrant and the Notice of
Exercise annexed hereto duly executed at the principal office of the Company (or
such other office or agency of the Company as it may designate) and upon payment
of the Exercise Price of the shares thereby purchased.

                                (i) Exercise by Payment of Exercise Price.
Payment of the Exercise Price may be made (A) by check or bank draft payable to
the order of the Company, (B) by wire transfer, (C) by cancellation of
indebtedness of the Company to the Holder hereof at the time of exercise,
including but not limited to the loans evidenced by the Note held by the Holder,
or (C) by any combination of the foregoing. If the amount of the payment
received by the Company is less than the Exercise Price, the Holder will be
notified of the deficiency and shall make payment in that amount within three
(3) business days. In the event the payment exceeds the Exercise Price, the
Company will refund the excess to the holder within three days of receipt.


<PAGE>

                     (b) As a condition to the exercise of this Warrant, the
Holder agrees to furnish or cause to be furnished to the Company such documents
and opinions of counsel as may reasonably be required to satisfy the Company
that the shares of Common Stock that are issued upon the exercise of rights
represented by this Warrant (the "Warrant Shares") may be issued to the Holder
pursuant to an exemption from the registration requirements of, and otherwise in
compliance with, applicable federal and state securities laws.

                     (c) Upon exercise, the Holder shall be entitled to receive,
promptly after payment in full or by net exercise, one or more certificates,
issued in the Holder's name or in such name or names as the Holder may direct,
subject to the limitations on transfer contained herein, for the number of
shares of Common Stock so purchased. The shares so purchased or received shall
be deemed to be issued as of the close of business on the date on which this
Warrant shall have been exercised. The Company may postpone for a period not to
exceed 90 days the time of delivery of certificates for the shares issuable upon
the exercise of this Warrant for such additional time as the Company shall deem
necessary or desirable to enable it to comply with the listing or quotation
requirements of any securities exchange upon which shares of the Company may or
are then contemplated to be listed on the National Association of Securities
Dealers, Inc., or the requirements of the Securities Act of 1933, as amended,
the Securities Exchange Act of 1934, as amended, any applicable rules or
regulations of the Securities and Exchange Commission or the requirements of
applicable state securities laws. Any shares of Common Stock issued upon the
exercise of this Warrant shall bear the restrictive legend set forth on the face
of this Warrant.

                     (d) The Company covenants that all Warrant Shares will be
fully paid, nonassessable, and free from all taxes, liens and charges in respect
of the issue thereof (other than taxes in respect of any transfer occurring
contemporaneously with such issue).

         3. No Fractional Shares or Scrip - No fractional shares or scrip
representing fractional shares shall be issued upon the exercise of this Warrant
unless this Warrant is exercised in full. In lieu thereof, a cash payment shall
be made equal to such fraction multiplied by the Exercise Price per share as
then in effect.

         4. Charges, Taxes and Expenses - Issuance of certificates for Warrant
Shares shall be made without charge to the Holder for any issue or transfer tax
or other incidental expense in respect of the issuance of such certificate, all
of which taxes and expenses shall be paid by the Company.


<PAGE>

         5. No Rights as Shareholder - This Warrant does not entitle the Holder
to any voting rights, dividend rights or other rights as a shareholder of the
Company prior to exercise and payment in full of the Exercise Price in
accordance with Section 2 hereof.

         6. Investment Representation - The Holder, by acceptance of this
Warrant, represents and warrants to the Company that this Warrant and all
securities acquired upon any and all exercises of this Warrant are purchased for
the Holder's own account for investment, and not with view to resale or
distribution of either this Warrant or any securities purchasable upon exercise
hereof.

         7. Sale or Transfer of the Warrant; Legend - Neither this Warrant nor
the Warrant Shares may be sold or transferred unless either (i) they first shall
been have registered under the Securities Act of 1933, as amended (the "1933
Act") and any applicable state securities laws and such sale is made in
accordance with, and pursuant to, such registration statement, or (ii) the
Company first shall have been furnished with an opinion of legal counsel
reasonably satisfactory to the Company to the effect that such sale or transfer
is exempt from the registration requirements of the 1933 Act and such state
laws. Notwithstanding the foregoing, this Warrant may be transferred by the
original holder hereof to any of its affiliates without the requirement of an
opinion of legal counsel, so long as such transfer is in compliance with federal
and state securities laws. Each certificate representing any Warrant or any
Warrant Shares that has not been registered and that has not been sold pursuant
to an exemption that permits removal of the legend shall bear a legend referring
to such restrictions on transfer, substantially in the form of the legend
affixed to this Warrant. Upon the request of a holder of a certificate
representing any Warrant Shares, the Company shall remove the foregoing legend
from the certificate or issue to such holder a new certificate therefor free of
any transfer legend, if, with such request, the Company shall have received
either (i) an opinion of counsel reasonably satisfactory to the Company to the
effect that such legend may be removed from such certificate or (ii) if
Paragraph (k) of Rule 144 or a substantially similar successor rule remains in
force and effect, representations from the Holder that such Holder is not then,
and has not been during the preceding three months, an affiliate of the Company
and that such Holder has beneficially owned the security (within the meaning of
Rule 144) for two years or more (or such shorter period as may then be specified
in Rule 144).

         8. Adjustments

                     8.1 Adjustments for Stock Splits, Reverse Stock Splits or
Stock Dividends - In the event that the outstanding shares of Common Stock shall
be subdivided (split), combined (reverse split), by reclassification or
otherwise, or in the event of any dividend or other distribution payable on the
Common Stock in shares of Common Stock, the Warrant Number in effect immediately
prior to such subdivision, combination, or dividend or other distribution, and
the Exercise Price per share, shall be proportionately adjusted. Adjustments set
forth herein shall be readjusted in the same manner for any successive event or
events described herein.


<PAGE>

                     8.2 Adjustment for Capital Reorganizations - If at any time
there shall be a capital reorganization of the Company or a merger or
consolidation of the Company with or into another corporation, or the sale of
the Company's properties and assets as, or substantially as, an entirety to any
other person, then, as part of such reorganization, merger, consolidation, or
sale, lawful provision shall be made so that the Holder of this Warrant shall
thereafter be entitled to receive on exercise of this Warrant during the period
specified in this Warrant and on payment of the Exercise Price then in effect,
the number of shares of stock or other securities or property of the Company, or
of the successor corporation resulting from such merger or consolidation, to
which a holder of the Common Stock deliverable on exercise of this Warrant would
have been entitled on such capital reorganization, merger, consolidation, or
sale if this Warrant had been exercised immediately before that capital
reorganization, merger, consolidation, or sale. In any such case, appropriate
adjustment, as determined in good faith by the Board of Directors of the
Company, shall be made in the application of the provisions of this Warrant with
respect to the rights and interests of the Holder of this Warrant after the
reorganization, merger, consolidation, or sale to the end that the provisions of
this Warrant (including adjustment of the number of shares purchasable on
exercise of this Warrant) shall be applicable after that event, as near as
reasonably may be, in relation to any shares or other securities or property
deliverable after that event on exercise of this Warrant.

                     8.3 Adjustments for Subsequent Equity Offerings - In the
event that the Company makes an offering of its equity securities subsequent to
the issue date of this Warrant, (an "Equity Offering"),

                     (a) the Warrant Number shall be adjusted to be equal to the
                     product derived by multiplying .20 by the quotient
                     resulting from dividing 1,000,000 by the New Securities
                     Purchase Price; and

                     (b) if the Value/Cash Ratio (as defined herein) of the
                     Equity Offering is greater than 1.50, the Warrant Number in
                     effect immediately prior to the Equity Offering, but after
                     giving effect to the provisions of Section 8.3(a), shall be
                     adjusted to be equal to the result of the following
                     formula:

                     (1,000,000/(Equity Offering Proceeds X 2.5/Fully-Diluted
                     Shares) - 1,000,000/((Equity Offering Proceeds + Pre-Money
                     Valuation)/Fully-Diluted Shares)) +.2 X (1,000,000/(Equity
                     Offering Proceeds X 2.5/Fully-Diluted Shares))

                     For the purposes of this Section 8.3,

                         (i) "New Securities" shall mean the securities offered
                     in the Equity Offering.

                         (ii) "New Securities Purchase Price" shall mean the
                     per-share purchase price of the New Securities.


<PAGE>

                         (iii) "Value/Cash Ratio" shall mean the quotient
                     resulting from dividing the Pre-Money Valuation by the
                     Equity Offering Proceeds.

                         (iv) "Pre-Money Valuation" shall mean the aggregate
                     pre-money valuation of the Company calculated on a
                     fully-diluted basis used to determine the New Securities
                     Purchase Price.

                         (v) "Equity Offering Proceeds" shall mean the gross
                     proceeds received by the Company from the sale of New
                     Securities, including proceeds received by conversion of
                     the Note or any other convertible instrument.

                         (vi) "Fully-Diluted Shares" shall mean the number of
                     shares of outstanding stock of the Company immediately
                     after the conclusion of the Equity Offering calculated of a
                     fully-diluted basis, taking into account all outstanding
                     convertible securities and shares reserved for issuance
                     under any stock option plans.

                         (vii) "Note" shall mean that certain Convertible Demand
                     Note in the principal amount of $1,000,000 of even date
                     issued by the Company to the Holder.

In the event that the terms of the Equity Offering provide for multiple
closings, the Equity Offering Proceeds shall be deemed to include the aggregate
proceeds of all such closings, and no adjustment shall be made to the Warrant
Number or Exercise Price pursuant to Section 8.3(b) until the conclusion of the
Equity Offering. The terms of this Section 8.3 shall automatically terminate
upon the conversion of the Note into New Securities, provided that such terms
shall apply to the Equity Offering in which the Note is converted.

                     8.4 Certificate as to Adjustments - Upon the occurrence of
each adjustment or readjustment pursuant to this Section 8, the Company at its
expense shall promptly compute such adjustment or readjustment in accordance
with the terms hereof and furnish to each Holder a certificate setting forth
such adjustment or readjustment and showing in detail the facts upon which such
adjustment or readjustment is based. The Company shall, upon the written
request, at any time, of any Holder, furnish or cause to be furnished to such
Holder, a like certificate setting forth: (i) such adjustments and
readjustments; (ii) the Exercise Price at the time in effect; and (iii) the
number of shares of Common Stock and the amount, if any, of other property that
at the time would be received upon the exercise of the Warrant.

                     8.5 Notices of Record Date - In the event of any taking by
the Company of a record of the holders of any class of securities for the
purpose of determining the holders thereof who are entitled to receive any
dividend (other than a cash dividend that is the same as cash dividends paid in
previous quarters) or other distribution, or any right to subscribe for,
purchase or otherwise acquire any shares of stock of any class or any other
securities or property, or to receive any other right, or any capital
reorganization of the Company, any reclassification or recapitalization of the
capital stock of the Company or any transfer of all or substantially all the
assets of the Company to or consolidation or merger of the Company with or into
any other person, or any voluntary or involuntary dissolution, liquidation or
winding-up of the Company, then and in each such event the Company will mail or
cause to be mailed to the holder of this Warrant a notice specifying (i) the
date on which any such record is to be taken for the purpose of such dividend,
distribution or right, and stating the amount and character of such dividend,
distribution or right, and (ii) the date on which any such reorganization,
reclassification, recapitalization, transfer, consolidation, merger,
dissolution, liquidation or winding-up is to take place, and the time, if any is
to be fixed, as of which the holders of record of any class of securities shall
be entitled to exchange their shares of securities for securities or other
property deliverable on such reorganization, reclassification, recapitalization,
transfer, consolidation, merger, dissolution, liquidation or winding-up. Such
notice shall be mailed at least ten (10) days prior to the date specified in
such notice on which any such action is to be taken.


<PAGE>

                     8.6 No Impairment - The Company will not, by amendment of
its Certificate of Incorporation or through any reorganization, transfer of
assets, consolidation, merger, dissolution, issue or sale of securities or any
other voluntary action, avoid or seek to avoid the observance or performance of
any of the terms of this Warrant, but will at all times in good faith assist in
the carrying out of all such terms and in the taking of all such action as may
be necessary or appropriate in order to protect the rights of the holder of this
Warrant against impairment. Without limiting the generality of the foregoing,
the Company (a) will not increase the par value of any shares of stock
receivable on the exercise of this Warrant above the amount payable therefor on
such exercise, and (b) will take all such action as may be necessary or
appropriate in order that the Company may validly and legally issue fully paid
and nonassessable shares of stock on the exercise of this Warrant.

         9. Reservation of Stock Issuable on Exercise of Warrant - The Company
will at all times reserve and keep available, solely for issuance and delivery
upon the exercise of this Warrant, all shares of Common Stock (or other
securities) from time to time issuable upon the exercise of this Warrant.

         10. Loss, Theft, Destruction or Mutilation of Warrant - Upon receipt by
the Company of evidence reasonably satisfactory to it of the loss, theft,
destruction, or mutilation of this Warrant, and in case of loss, theft, or
destruction, of indemnity or security reasonably satisfactory to it, and upon
reimbursement to the Company of all reasonable expenses incidental thereto, and
upon surrender and cancellation of this Warrant, if mutilated, the Company will
make and deliver a new warrant of like tenor and dated as of such cancellation
in lieu of this Warrant; provided, however, if any Warrant of which the original
holder, its nominee, or any of its partners or affiliates is the registered
holder is lost, stolen or destroyed, the affidavit of the registered holder
setting forth the circumstances with respect to such loss, theft or destruction
shall be accepted as satisfactory evidence thereof, and no indemnification bond
or other security shall be required as a condition to the execution and delivery
by the Company of a new Warrant in replacement of such lost, stolen or destroyed
Warrant other than the registered holder's unsecured written agreement to
indemnify the Company.


<PAGE>

         11. Remedies - The Company stipulates that the remedies at law of the
holder of this Warrant in the event of any default or threatened default by the
Company in the performance of or compliance with any of the terms of this
Warrant are not adequate and may be enforced by a decree for the specific
performance of any agreement contained herein or by an injunction against a
violation of any of the terms hereof or otherwise.

         12. Dissolution. - In the event of any dissolution of the Company
following the transfer of all or substantially all of its properties or assets,
the Company, prior to such dissolution, shall at its expense deliver or cause to
be delivered the stock and other securities and property (including cash, where
applicable) receivable by the Holders of the Warrants after the effective date
of such dissolution pursuant to this Section 12 to a bank or trust company
having its principal office in Boston, Massachusetts, as trustee for the Holder
or Holders of the Warrants. Such bank or trust company shall be appointed by the
Company, by written notice to each Holder of a Warrant, for the purpose of
issuing Common Stock (or other securities) on the exercise of the Warrants,
exchanging thereafter any such issuance, exchange or replacement, as the case
may be, shall be made at such office by such Warrants pursuant to this Section
12, such bank or trust company shall have all the power and duties of a warrant
agent appointed pursuant to this Section 12 and shall accept, in its own name
for the account of the Company or such successor person as may be entitled
thereto, all amounts otherwise payable to the Company or such successor, as the
case may be, on exercise of this Warrant.

         13. Notices, etc. - All notices and other communications from the
Company to the holder of this Warrant shall be mailed, by first class mail, to
such address as may have been furnished to the Company in writing by such
holder, or, until an address is so furnished, to and at the address of the last
holder of this Warrant who has so furnished an address to the Company (and shall
be deemed effective on the third day following the date of mailing). All
communications from the holder of this Warrant to the Company shall be mailed by
first class mail to the Company at it principal business address, or such other
address as may have been furnished to the holder in writing by the Company.

         14. Miscellaneous - This Warrant and any term hereof may be changed,
waived, discharged or terminated only by an instrument in writing signed by the
party against which enforcement of such change, waiver, discharge or termination
is sought. This Warrant shall be construed and enforced in accordance with and
governed by the laws of the State of Delaware. The headings in this Warrant are
for purposes of reference only, and shall not limit or otherwise affect any of
the terms hereof. This Warrant is being executed as an instrument under seal.
The invalidity or unenforceability of any provision hereof shall in no way
affect the validity or enforceability of any other provision.

         15. "Market Stand-Off" Agreement - The Holder (and any permitted
transferee hereunder) hereby agrees that it will not, without the prior written
consent of the managing underwriter, during the period commencing on the date of
the final prospectus relating to the Company's initial public offering and
ending on the date specified by the Company and the managing underwriter (such
period not to exceed one hundred eighty (180) days) (i) lend, offer, pledge,
sell, contract to sell, sell any option or contract to purchase, purchase any
option or contract to sell, grant any option, right or warrant to purchase, or
otherwise transfer or dispose of, directly or indirectly, any shares of Common
Stock or any securities convertible into or exercisable or exchangeable for
Common Stock (whether such shares or any such securities are then owned by the
Holder (or any other party bound by this Section 15) or are thereafter
acquired), or (ii) enter into any swap or other arrangement that transfers to
another, in whole or in part, any of the economic consequences of ownership of
the Common Stock, whether any such transaction described in clause (i) or (ii)
above is to be settled by delivery of Common Stock or such other securities, in
cash or otherwise. The foregoing provisions of this Section 15 shall apply only
to the Company's initial public offering of equity securities and shall not
apply to the sale of any shares to an underwriter pursuant to an underwriting
agreement. The underwriters in connection with the Company's initial public
offering are intended third party beneficiaries of this Section 15 and shall
have the right, power and authority to enforce the provisions hereof as though
they were a party hereto. In order to enforce the foregoing covenant, the
Company may impose stop-transfer instructions with respect to the securities of
the Holder (and the shares or securities of every other person subject to the
foregoing restriction) until the end of such period.


                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]




<PAGE>



         IN WITNESS WHEREOF, the Company has caused this Warrant to be executed
in its corporate name by its duly authorized officer and to be dated as of the
issue date set forth on the first page of this Warrant.

Attest:                                      GIGABEAM CORPORATION


                                             By:________________________________
                                             Name:______________________________
                                             Title:_____________________________


[CORPORATE SEAL]



<PAGE>



                          NOTICE OF EXERCISE OF WARRANT



TO:  GIGABEAM CORPORATION

         (1) Pursuant to the terms of the attached Warrant, the undersigned
hereby elects:

         ______            to purchase ______ shares of Common Stock of GIGABEAM
                           CORPORATION (the "Company"), by the tender herewith
                           of payment of the Exercise Price of such shares in
                           full.


         (2) Please issue a certificate or certificates representing said shares
in the name of the undersigned or in such other name(s) as is/are specified
immediately below or, if necessary, on an attachment hereto:

                           Name                 Address
                           ----                 -------




DATE:  _____________________


HOLDER:  ________________________________________


<PAGE>



                               FORM OF ASSIGNMENT
                   (To be signed only on transfer of Warrant)



TO:      GIGABEAM CORPORATION

         For value received, the undersigned hereby sells, assigns, and
transfers unto ___________________________ the right represented by the within
Warrant to purchase shares of equity securities of GIGABEAM CORPORATION, as
described in the Warrant, and appoints ___________________________ attorney to
transfer such right on the books of GIGABEAM CORPORATION with full power of
substitution in the premises.



Dated:  ___________________________


Printed Name:  __________________________

Signature:  _______________________________
(Signature must conform to name of Holder as
specified on the face of the Warrant)

Address:  _______________________________-

_____________________________________


Signed in the presence of:


_____________________________________