I discovered LibraryThing yesterday. It lets you create an online catalogue of your personal library. And you can post and read reviews, click on the books to buy them from Amazon, as well as get in touch with people who have similar libraries. Pretty neat.
I've begun adding my books to LibraryThing. It'll take a while though, as I have a lot of books and no barcode scanner. I have to enter them all manually, though even that is made quite easy.
Check out my library (in progress) on the right hand side of my site, near the top.
