Goodreads is my latest geeky obsession. I have always been an avid reader, but have never really kept track of what I've read. Until now, that is! Goodreads provides virtual shelves for people to keep track of what they've read, what they want to read, what they're currently reading, etc. Adding a book to my shelves gives me a thrill that is similar to what I feel when browsing libraries.
Just about every book that you can think of is listed, along with reviews and ratings. Authors often have pages for themselves, so you can view the books they like. There's also an option to recommend books to people you've added as a friend.
If you're obsessed with reading, you should really, really sign up.