> Man I just looked at this for the first time today.  What this ignores is
> the fact that you can not sign away basic rights granted by the
Constitution
> in an agreement. This is clearly an obstruction of freedom of speech.

A point of clarity might be made here: In truth, contracts are a way to
specifically limit rights which are given to you by the Constitution. If you
are under contract not to speak about a certain topic, no 'freedom of
speech' clause in the Bill of Rights will intervene in your behalf.

For the duration of the contract, you are liable to its terms: a contract is
called 'private law' and while there are certain rights which can never
be taken away (where those begin an end changes over time and has a
lot to do with how informed about their rights a jury is), contracts simply
are a way to take away rights for a duration. It's a good reason to be
very careful about every contract you enter. The point that a shrink-wrap
contract may not be valid, is a good one.  But the point that a contract
cannot take away rights?  Sorry. If that is true, what is the purpose of a
contract?

Think about it. IANAL, but ICRTFM; it's all public-domain.

Here's some legalese, from www.law.cornell.edu:

<snip>

Contracts: an overview

Contracts are promises that the law will enforce. The law provides remedies
if a promise is breached or recognizes the performance of a promise as a
duty. Contracts arise when a duty does or may come into existence, because
of a promise made by one of the parties. To be legally binding as a
contract, a promise must be exchanged for adequate consideration. Adequate
consideration is a benefit or detriment which a party receives which
reasonably and fairly induces them to make the promise/contract . For
example, promises that are purely gifts are not considered enforceable
because the personal satisfaction the grantor of the promise may receive
from the act of giving is normally not considered adequate consideration.
Certain promises that are not considered contracts may, in limited
circumstances, be enforced if one party has relied to his detriment on the
assurances of the other party.

Contracts are mainly governed by state statutory and common (judge-made) law
and private law. Private law principally includes the terms of the agreement
between the parties who are exchanging promises. This private law may
override many of the rules otherwise established by state law. Statutory law
may require some contracts be put in writing and executed with particular
formalities. Otherwise, the parties may enter into a binding agreement
without signing a formal written document. See § 110 of The Restatement.
Most of the principles of the common law of contracts are outlined in the
Restatement Second of The Law of Contracts published by the American Law
Institute. See Restatement (Second) of Contracts. The Uniform Commercial
Code, whose original Articles have been adopted in nearly every state,
represents a body of statutory law that governs important categories of
contracts. The main Articles that deal with the law of contracts are Article
1 (General Provisions) and Article 2 (Sales). Sections of Article 9 (Secured
Transactions) governs contracts assigning the rights to payment in security
interest agreements. Contracts related to particular activities or business
sectors may be highly regulated by state and/or federal law.See Law Relating
To Other Topics Dealing with Particular Activities or Business Sectors.

In 1988, the United States joined the United Nations Convention on Contracts
for the International Sale of Goods which now governs contracts within its
scope.