I just stumbled across LibraryThing and it seems like a pretty decent/useful site. At first glance it seemed a little sketchy – in order to register you simply type in a username and password, click submit, and tada, you’re registered! Luckily most of my library is catalogued with Delicious Library so all I had to do was import the text file from there. I’m going to try it out over the next few days as I’ve been looking for a better way to organize my books online. Maybe I’ll play around with the API and see if I can get anything useful out of it.