If you haven't played around with this, you can get to it from my sidebar. Welcome to the most fun procrastination you've had in a long time, my bookloving friends... (says the professor who should be doing any number of things other than adding books to her library online....)
edited to add:
Ok, so now I've got to make a decision about whether to pay to become a member of the Library Thing. Because I've barely scratched the surface of all of the books that I own, and I've hit the limit of 200 that stands for free accounts. God, I've got a LOT of books.
4 years ago