Anyone who knows me knows I love books. Yup, I'm one of those people who can't go to a garage sale, flea market, Value Village, used book stores, and, yes, Chapters, Borders, Daltons, and any other chain you can think of, and not come out with a bag of books. 13 years ago I valued my books for insurance purposes and was shocked. It's way worse now. The main problem is I have mostly text books and tech references, which are pretty pricey.
As the title says, I found and instantly loved LibraryThing.com. It took a few nights of entering a stack at a time – and I have a few more to go – but most of my books are in there now. It's cool to compare and match against other people's library, read their reviews, and try the suggestor and unsuggestor tools. If you are a bibliophile, check it out. Also, check out Alberto Manguel's Massey Lectures. CBC's Ideas program broadcast and podcasted them (http://www.cbc.ca/ideas/massey.html).