LibraryThing Rocks!

LibraryThing is a free service for storing information about your personal library. It's the best thing to come along for collectors since the death of the card catalog.

You can download generic information about your books by performing an ISBN search in the "Add Books" section, which draws on book information stored by Amazon.com and libraries from around the world. You can add cover pictures from various uploaded user files or from Amazon. There are spaces for Library of Congress and Dewey Decimal System numbers, just in case you're as obsessive as I am about shelving your books.

The tagging feature allows you to categorize your books your own way, an especially handy feature for collectors. You're not limited to the old standbys like "History" and "Fine Arts"; you can group your books by "Red covers" or "Aunt Muzzy's Legacy," if you like.

You'll also find out how (un)common you are. The books listed also have notes attached telling you who else shares your passion for Jane Austen or books on prunes.

And no, they're not paying me to say this. It's just incredibly useful. I recommend it highly.