Book Army
Read and write book reviews, keep track of what you're reading, and connect with authors.
Goodreads
See what your friends are reading. Keep track of what you've read and organize your book lists into shelves. Join a book club to discuss your favorite books online.
LibraryThing
Catalog your books online, easily, quickly and for free.
Reading Trails
Browse a network of intersecting trails to discover what to read next.
Shelfari
Build virtual bookshelves, discover, rate and discuss books, and participate in online groups.