LibraryThing is quite possibly the coolest site I’ve come across in awhile (del.icio.us is awesome, but I’ve known about it for quite awhile). With LibraryThing you can keep an electronic catalog of all your books online, accessible from anywhere. As with any true Web2.0 application you can tag your books, view others’ tags for books, view others’ libraries and read reviews that other members have written.
Mandy and I recently made an account, we’ve added around 150 books to our library and its pretty neat. I’ve already discovered several people I already knew on LibraryThing (Art, Denise, I’m looking at you!). I’m a huge fan of books, so this has been intensely excited. The possibilities are pretty cool. Be watching for some widgets coming to my blog from LibraryThing. I’d encourage anyone who has a sizable library or who has been looking for a nice electronic catalog system to explore LibraryThing. The electronic catalog is worth it alone, the social and tagging aspects only sweeten the deal. The only drawback is that you can only store 200 books with a free account. I hesitated to say drawback, because for $25 you can get a lifetime membership that allows you to store an infinite amount of books.