Yesterday I signed up for a service called Library Thing, which seems to be a way to catalog one's book collection or personal library in a manner similar to what Flickr does for digital photos. My catalog (or the beginnings thereof) can be viewed here. The interface is kind of neat, and it's actually pretty easy to add books thus far (although I have not yet attempted to add some of my more hard-to-find books). It also allows for tagging of books and of browsing the libraries of others, which might be a nifty way to find reading recommendations.
I'm hoping to add a few books a day for a while.