The Librarything

LibraryThing is an online service to help people catalogue their books easily. You can access your catalogue from anywhere - even on your mobile phone. Because everyone catalogs together, LibraryThing also connects people with the same books, comes up with suggestions for what to read next, and so forth.

It searches the Library of Congress, Amazon and more than 45 world libraries. You can edit your information, search and sort it, "tag" books with your own subjects, or use the Library of Congress and Dewey systems to organize your collection. LibraryThing can also be a social space, described as "MySpace for books". You can check out other people's libraries, see who has the most similar library to yours, swap reading suggestions and so forth. LibraryThing also makes book recommendations based on the collective intelligence of the other libraries.

It is largely devoted to individuals cataloguing their books at home so does not have much coverage in science. As it grows however this may change, and they are already developing group features so that they can accomodate organisations that want to use the service.

Have a look here at:
http://www.librarything.com