LibraryThing is a wonderful tool for those of us who have a lot of books. Since I just (well, okay, two months ago) moved into a new house, I’ve been cataloging my books as I unpack. Granted, I’ve only unpacked two of my many boxes of books, so I’ve got a long way to go, but I’m having fun!
For anyone else who has a few “too many” books (like there’s really such a thing), LibraryThing is a good tool. I like that you’re not limited to using it for books you own; you can create a list of books you want to read, books you’ve read but don’t own, books you’ve sold—whatever you can come up with. I've found it really helpful that I can sort by author, title, publication date, etc. It's helping me find gaps in my collection (or, possibly just boxes I haven't unpacked yet).
Check out my list and see what you think!