Visual Music Search Engine
An interesting Flash-powered visual search engine for music artists. Enter your favorite band, and the site displays a bubble chart showing similar bands. The bigger the bubbles, the more popular that artist is. Many of the relationships are pretty obvious, but you may be able to find a few new bands through the site.
Gnoosic is a similar site, though it isn’t as visually oriented. I think it goes into more detail though, and perhaps covers more indie bands.