I posted this link in another discussion about SOPA/PIPA, but it's important enough that I think it needs to be posted here, too. When you click on this link, it will take you to a list of states. Find your state and click on it and it will give you a list of your federal Congressmen/women and their position on SOPA/PIPA. If you click on their name, it will give you detailed information including contact information:

http://projects.propublica.org/sopa/states

Don't forget to send a quick message to those who oppose SOPA/PIPA thanking them for their decision while you are discussing these laws with the others.