Library Thing is great tool for not only your personal home collection, but also for the benefit of cataloging your favorite books with tags and mashups. I started a list of some of my favorite children's books that I've done for story times. This will be a fairly timing-consuming process, but it will be worth it when I have my own archive of very workable books I've done in the past.
I can then recycle some of them by using my mashups and tags to broaden my units. This is a tool that will be very valuable to me for years to come!