I'm completely in love with LibraryThing. I mean, yes, I have been a hardcore reader my whole life, and I am in library school now, so I am slightly predisposed to loving something as geeky as a website where you catalog your own books. But for me, it's more about the community where I can talk about what I'm reading - be it the latest bestseller or some obscure tome. I've been a LT member since June 2006 and have managed to get all 640 of my books cataloged.
Besides all the cataloging fun, LibraryThing also runs book pile contests every once in a while. These are my first entries, to this month's Groundhog's Day pile contest. While the books themselves aren't particularly in step with the holiday, I hope the pictures are at least a little amusing.
All the entries can be seen here.
The books on top are the Archaologische Bibliographie 1990-1993, from the library in my office. The books on the bottom are my Dark Tower books, an amazing series by Stephen King. I just started rereading the series for the first time since it was finished. If you haven't read them, now's a good time ;)