LibraryThing is an online book catalog and meeting place for book lovers. You can list your books, either your reading list or books you own. Up to 200 books can be listed for free; unlimited title listing is available for $10 a year. It will also recommend books you might like, based on your own book listings.
You can tag your books for easy searching and easy connecting with like-minded bibliophiles. For the truly obsessive, you can arrange and catalog with Library of Congress and/or Dewey listings. What fun!
You can also list books, with cover graphics, on your own blog, with a downloadable widget. You can check your library listings, on your cell phone, while standing in a library or book store. And LibraryThing touts itself as a MySpace for booklovers--a virtual social networking site. Sounds like my kiind of people.