Like MySpace, but for people who can read

I think the idea behind this website is effing brilliant: catalog your book collection and then get recommendations on other books you might like based on overlap with other people's collections (that's collaborative filtering, people... like what Amazon does, but not colored by the textbooks or gifts you bought that you'd never choose to read for yourself). There's a little bit of social networking, but I like the fact that the website isn't focused on collecting 'friends'. WSJ article about it (free) here.