This reminded me of Delicious Library, a program for the Macintosh for
cataloging your home library.

http://www.delicious-monster.com/

"Get your Mac, a webcam, and Delicious Library and rediscover your
home library. Just point any FireWire digital video camera, like an
Apple iSight, at the barcode on the back of any book, movie, music, or
video game. Delicious Library does the rest. The barcode is scanned
and within seconds the item's cover appears on your digital shelves
filled with tons of in-depth information downloaded from one of six
different web sources from around the world."

I couldn't find a list of what these sources were. However, early on
(2004), they were using Amazon's API to pull cover images, etc.

http://arstechnica.com/reviews/apps/delicious-library.ars

On 11/2/06, Jonathan Rochkind <[log in to unmask]> wrote:
> My suggestion for an even better scenario: A person grabs a book off the
> shelf, and enters the ISBN into an application they use for dealing with
> books.  (LibraryThing, Desktop home cataloging software, professional
> cataloging software (!), firefox extension, local library web page, or
> the OpenFRBR web site itself). The application contacts OpenFRBR behind
> the scenes and checks all available....
>
> Think of the way the CDDB works.

--
Tom