Used Math Textbooks

What is the best site for selling used textbooks?

Like countless other students, I was screwed because the textbook publishers decided to release new editions, making it impossible to sell my textbooks at the school bookstore. I'm curious which site is the best for selling my used (but in perfect condition) textbooks online. Keep in mind, the highest prices are what matters most.

Public Comments

1. cheapbooks.com has a search engine for selling your books to other websites to see who gives you the best price. Don't expect much if the books are outdated though.
2. Amazon.com might be worth looking into.
3. cash4books.com. I've used them before and they're really good. They pay for shipping and everything, you just have to pack them up!
4. half.com
5. My son has had pretty good luck on E-bay