http://www.librarything.com/catalog/vrsteffen This is now my new fav. 2.0 exercise. I really enjoyed adding my books to the catalog, and seeing how many people had the same titles, It also helped me organize a portion of my own collection, the tags were very handy; though I'm afraid if I added all my books I would have to upgrade to a payed account. I also joined the librarians who librarything group, which had a few interesting topics up for discussion. If or when I have more time I think I may have to add comments about my titles.