i always learn about cool things at knit night, and last week, the ultra cool rose shared the most awesome web site with us all. LIBRARY THING. Yes, LIBRARY THING! It's so amazing. You can catalog your own private library collection, tags your books similarly to Flickr, etc.. . . . my weak descriptions do not do it justice. just go ahead and try it already! not convinced? here's the official info from their website:
Catalog your books online
Easy. no software required.
Powerful. LibraryThing mines the full Library of Congress catalog—ideal for collectors and scholars.
Free. Enter 200 books for free; lifetime membership $10 (beta special).
Tagged. LibraryThing allows blog/Flickr-style tagging
Shared. Show everyone your library, or keep your library private. You can even put a widget on your blog to show people what you're reading.
Safe. LibraryThing's not going away, but you can export your data.