If it is a contract you can't accept, "leave it" is the correct option. (assuming you have other possible work)
Very few people have the clout to ask for changes.
It doesn't take clout. Just big ****s. I have asked for changes in consulting contracts (non-disclosure, non-compete, and other terms) from some major corporations. The answer is usually NO and you have to make the choice described above. However, in one case I objected to a contract handed to me by a big company purchasing department, and it resulted in a meeting with a lawyer and a modification of the contract. (The original contract was written by her predecessor).
So if you can't live with the contract, ask to change it or just leave. It can't hurt to ask for a change as long as you are prepared to walk away.
out-lawyer (is this even a word ;)?
It is now.
The issues of enforcement of the NC and whether or not Google is a competitor will be interesting to follow. Neither company will be out-gunned. With people in the computer related industries (as well as most others) frequently changing jobs, this could have meaning for many of us.