6 months is pretty standard for non-compete, at least in some areas for DIRECT competition. 2 years is insane. I would cross out the sections you do not agree with and have someone initial all the changes before I would sign it.

A lot of times they just put stuff in their to cover their asses and hope people don't even notice, and I'm sure plenty don't. At Dreamworks I know they have first refusal to anything creative in nature that you come up with while working there. Lucky for me I never had to sign one.

Others have correctly suggested that in most cases, the noncompete parts of the contract are completely unenforceable. This varies by state of course so check your local court records (search by the section code related to the noncompete law). Ethics and intent is generally what plays a role, and fortunately there are some ethics in our industry. If you quit after three weeks, take their client lists, and underbid them, expect to get into some trouble. But if you part amicably after 2yr and work in the same field, do not worry about working for a direct competitor and making contact with people you've met. This happens all the time.