Paperbackswap.com provides a forum for book lovers to trade and exchange books for free (not counting shipping costs). Registered members can list titles they would like to read and browse the 4 million books owned by other members.
Shelfari.com connects bookworms through their own social network. Members can list their favorite books and view others’ book lists. They can also read members’ reviews and keep up on new releases.
Librivox.org allows users to rest their eyes and let others do the reading for them. The site’s free, downloadable audio books have been compiled by volunteers, who record themselves reading individual chapters of books. All texts are in the public domain—so there’s no need to worry about copyright infringement or royalty costs—and anyone can add his or her own voice to the collection.
Source: Popular Science