Used Math Textbooks

What is the best place to buy used college textbooks?

Other than amazon.com, where do most college students get their textbooks cheap? Is there lots of borrowing from upperclassmen?

Public Comments

1. I just got my nursing license, and I saved a BUNCH of money from www.half.com I got all of my books there for a fraction of the price and they were all in very good shape.
2. A number of the campus bookstores sell the textbooks used. I'd try there first. Otherwise, look on different bulletin boards around the campus.
3. If you're lucky, directly from an upperclassman. Otherwise at the bookstore.