Forbes.com reports on a soon-to-debut application called Pixserve, developed by a company called Pixlogic, that can find images by analyzing their visual content. Users point to an image and ask Pixserve to find similar images in the database.
At this point, Pixlogic hopes to license Pixerve to imaging software companies such as Kodak, HP, Apple, and Adobe, rather than sell it directly to consumers, but the Forbes.com article doesn't mention any confirmed licensing agreements.