It's one of the coolest "social network" sites on the net, and others agree. If you are anything like me, when you get invited to visit someone's home, one of the first things you do when you get the chance is to browse their bookshelves.
LT isn't the best for keeping track of your own books for your own cataloging. (For that I recommend Delicious Library.) But once you do have your own catalog, drop it into LT (it can convert from almost anything), and start getting social about our solitary pleasure of reading. You can't even claim that cataloging your books is "too hard". You can buy an old CueCat for a few bucks, or a nice wireless bluetooth smart scanner for more, or use a Mac iSight with DeliciousLibrary, and quickly scan your barcodes. If you have a lot of books, you ought to catalog them anyway, for your own sanity.
The site is neat, fast, slickly "Web 2.0" and is all AJAX-ified and tag-enabled and folksonomy-oriented. It's constantly adding neat new features, without getting messy or cluttered, and it's obviously run by people who love it, instead by corporate drones who are grinding out work to collect "eyeballs" and "maximize revenue".
My own LT account is, of course, FallenPegasus. What's yours? Chime in on the comments, and let me know.