If you or someone you know are getting ready to take college courses (or currently attending), there's a great website from which to rent all of your books! Campusbookrentals.com offers free shipping both ways and has flexible renting periods. The best feature is that you can highlight in the textbooks--which is really helpful for those courses that are reading intensive. Check out CampusBookRentals.com to save 40-90% off bookstore prices without the hassle of having to store books or resell them after the semester is over. Renting a textbook allows you to save a lot of money and get rid of it once it's no longer needed.
Here are two examples I've taken from my alma mater, MIZZOUFor the summer 2012 semester, Chemistry 1310 (general chemistry) requires the 11th edition of Chemistry by Chang. The MU Bookstore sells the book for $233.65. You can rent it from CampusBookRentals.com for $149.78 for the summer, or a bit higher if you need the book for a quarter ($156.66) or semester ($172.16).
My degree is in math education, so one semester I took Math 2320 (Discrete Math Structures). That class at Mizzou requires the 5th edition of Discrete Mathematics by Ross. The MU Bookstore sells it new for $88 and used for $66--OR you could rent it from CampusBookRentals.com for $36.40 (summer), $38.07 (quarter), or $41.84 (semester).
CampusBookRentals.com also donates to Operation Smile with each textbook rented, so feel good about getting your textbooks from them since they help make a difference.