LibraryThing and its predecessors

LibraryThing is an online catalog for your books. The earliest implementation of an idea like this may be the San Francisco Bay area's Distributed Library Project (Mike Benham, 2002) which lets you find a book in the hands of a private owner near you. Now imagine if something like WorldCat.org would search not only libraries but also the Distributed Library Project and LibraryThing.

WorldCat.org

WorldCat.org lets you find a book, journal, or journal article in the libraries nearest your ZIP code.