As Brian says, it does lack in the social and recommendation realms, but it does very well apart from that. One of the things I specifically like about it is how the borrowing part works (and this was a consideration because I lend out DVDs often and can be forgetful): You just indicate that a person has borrowed an item, and it adds an “out” tag to that item’s display AND automatically inserts an event into your iCal for when the item should be returned.

And forget buying a bluetooth barcode scanner. It’ll scan barcodes from a webcam! And MacBooks have built-in webcams! Woo!

It doesn’t specifically track borrowed books, but it’s all about tags, so it’s easy to tag them “borrowed” or “source:library” or whatever.

Does LibraryThing also track checkouts/borrows? I couldn’t tell from the website.

Current count: 554 books, 506 DVDs