Whether you're looking for a new book to read or can't stop gushing about an old favorite, there are sites to help you feed your lit addiction, whether they're read on your Kindle, iPhone or simply printed on paper. Here are our five favorites, offering a variety of sharing, cataloging and discovery tools that may help lead to your next favorite book.
GoodReads is one of three social sites we'll recommend here; of the three, we've found it the most useful for a balanced blend of managing what books you're reading, intend to read and have completed, and what you thought about them, as well as sharing that information socially. They appear to be developing a recommendations system, but so far finding books rated highly by friends has served.
If you prefer your social reading to have an encyclopedic component, Shelfari is the resource for you. Each book's page has a seriously intense breakdown of every element of the book, including locations, characters, the first sentence, and edition info. It's run by and integrated with Amazon, so the site also includes "similar to" and "other users who liked this book purchased" recommendations.
LibraryThing is like a well-organized book club with millions of people. With many of the same social elements as Goodreads, and the well-tuned recommendations offered by Shelfari, it's a good option for people who are willing to pay for the service; the first 200 books are free, and after that it's an annual fee of $10 or a one-time lifetime fee of $25.
BookCrossing is a site for book borrowers and lenders, for whom the four-walled confines of the library is no longer enough. Users register an individual book into the BookCrossing system, then release it into the wild by leaving it in a public place, or "catch" it by hunting down the location of a book that has recently been dropped. Users can make requests, and people often find themselves buying multiple copies of a book they love just to share it out again through the BookCrossing system.
GetGlue is the FourSquare of media; when you're watching a movie or, in this case, reading a book, you can "check in" to the site, which will post updates to your Twitter and distribute "stickers" as achievements for completing specific actions or activities. Based on the collective data, the system can make recommendations of all types of other media that you might enjoy. If you're less interested in building a library but still want to reap the rewards of accumulation, this is your site.