I enjoyed very much LibraryThing, it was a treat for those who have a considerable collection of books and have a hard time to catalog and classify. I was able to set up an account and play around performing searches, tagging, reading reviews, etc.
Last year I had a hard time organizing the books that were in my classroom, that belonged to the unit itself. I had to look for help to find a way to classify and keep record of it's location. I thought about doing it a database or a spread sheet. Well, LibraryThing is going to make it very easy for me to create the catalog, classify, tag, share, etc. I can make it a classroom activity, to have students think of tags for each book, make them think of the classification for each book, and add them to the collection.