Wow. Google has just announced an incredible new service on the official Google Blog.
Book lovers rejoice, you can now create a virtual library of your book collection using Google's Book Search. You can maintain your entire collection by adding books using ISBNs, using Book Search, or copying from other people's libraries.
Once added, books can be rated, tagged, and reviewed, and you can browse in cover view, detail view, filter by tag, and search your library. Viewing a book's details gives you a varied wealth of information, including book publishing details, online reviews, online references, references from other books, regularly quoted passages, related books, and in some cases even a map of places mentioned within the books pages.
Your library is public (my library) so you can share your collection with your friends, or use your friend's collections as inspiration for your own reading. There's even an RSS feed of new additions and an XML feed of your collection to download or mashup in your own applications. The XML feeds include ISBN, author, title, your tags, reviews, and rating -- the RSS feed also includes the cover art.
At the moment it's a little US-centric, with cover art and detailed book details missing for books published overseas -- which is a bit of a problem for those of us in the UK or Australia. That's not going to stop me from importing my 1000 book database into My Library later tonight though!
I hope they extend the data feeds further. I'd dearly love to be able to add books to my collection (and rate, review, and label them) using a GData feed like PicasaWeb; I'd also love to have access to some of the wealth of book information Google have aggregated for each book. In fact, while we're at it, I think they should extend 'My Library' to include music and movies I own as well as books.
I don't know many people that were big users of Google Books, but just about everyone I know with a collection of more than 100 books has some way of cataloging their books (Excel spreadsheets, custom software, etc). I think this is a wise move precisely because it gives people a new reason for regularly visiting the site.