"Catalog your books online
* Easy. Catalog your books online (example); 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 (example).
* 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."
