My favorite so far is from TheOatmeal; their page has a good, simple explanation of the problem and explains it through their normal medium.
Don't forget that SOPA isn't officially dead until the end of the year, even if Eric Cantor has 'tabled' it for the moment. Write your congresspeople. Be heard. Make sure they never come back to this thing while they work for you.
And while you're writing letters to your congresspeople, write slashdot's editors and ask why they haven't done something about SOPA themselves. They buckled for scientology when that 'church' threatened the existence of slashdot, explaining their motives and urging readers to write their congresspeople; why won't they take the same public stance on something that threatens the entire internet?