The Internet Archive’s Map of Book Subjects
This map offers an alternative way to browse the 2,619,833 images contained in the Internet Archive’s book collection. It shows 5500 different subjects which have been algorithmically arranged by their thematic relationships. The size of each link resembles the amount of images that are available for that topic. Clicking on a link will open the flickr page containing all the pictures for that subject.
http://incubator.quasimondo.com/internetarchive/InternetArchiveBookSubjectsMap.html