Finding Similar Images

I admit it. Like anyone else with a decent-speed connection to the Internet, I collect a lot of images. For example, a few months ago, I described a program that looks through Yahoo! news images for pictures of Oregon and some of my favorite singing stars. Sometimes, an image travels multiple paths before it ends up on my disk, and thus gets saved under different names. But that’s a waste of disk space, so I want to eliminate duplicates where I can.