"I'm a voter in Congressman Rush's district, and I'm calling to ask the Congressman to vote against SOPA, HR. 3261. As the owner of an internet business in Chicago, I fear that I'll be forced to close shop if SOPA passes. SOPA would make it easy for anyone to have my websites shut down, without having to prove that we've violated any law. Our only recourse would be an expensive legal process that we simply can't afford. Thus, if SOPA passes, my company and others like it will be out of business, and many people will be out of work."
Also, EFF makes it dead-simple to email the right politicians based on your address. They even have a template email for you. You can be done in under a minute:
https://wfc2.wiredforchange.com/o/9042/p/dia/action/public/?...
BTW, if you're afraid to call in because you think you'll sound silly/scripted/unimportant, don't be! The people who answer phones at political offices get lots of calls, and they're used to hearing all kinds of weird stuff. Believe me, even if you read your script in a Ben Stein monotone, you'll still sound twice as smart and engaging as a lot of what they hear. So don't be afraid to call your politicians.