The books are free. The shipping is free. And you're free to select any title from a library of more than 1 million books. What's the catch? You'd need to run away from home to have enough time to read every single one. The process is simple:Register online and list at least nine books you want to swap. You get three credits just for doing that. Then every time you send out a book, you get a credit to order a book of your choice. You pay the postage when you mail the book and the people you order from will return the favor. It's like having the run of the library. And you don't even have to keep your voice down.

PaperBackSwap.com