Colorjack Sphere
I don't know about you, but I don't understand much about colors and how they interact, and when I'm working on web pages that want to look spiffy I never know how to pick colors that work well together.
This Sphere thingy on the Colorjack site looks like it will help a lot!
Nice. I've seen a lot of similar tools and have looked at some color theory, but this puts it all together well. I'll try it when I need some color inspiration. :)