I discovered this site through StumbleUpon and thought I'd share here. It's really cool.
You start off by entering a tag. I started off with “Indy 500”. Once you click “Go”, the fun starts. You are whisked away to what looks to be a star, in this case labeled "Indy 500", surrounded by planets that represent complementary tags such as Indycar, Indiana, Indianapolis and Race. If you’re happy with your initial search, you can just click the star and you'll be zoomed in to a globe that quickly propagates with images related to that tag, but if you click on one of the planets, you’ll zoom into a specific set of image results associated with one unique tag. Drilling down to that sphere brings you to another galaxy cluster centered with a star and even more orbiting planets. You don’t necessary have to view pictures. The visual treats preceding any image browsing are enough to wow you. Link.