Colour Scheme Designer
I think someone may have already posted this up .... but just in case:
That is pretty snazzy. I showed this to my girlfriend (who does all manner of artish things) and she pointed me towards the Adobe version of this kind of thing. Apparently you can save the color schemes into photoshop and the like as well.
You can indeed save adobe swatches for later use with kuler. It's basically the same thing as the color-wheel tool in illustrator. A useful little beast sometimes ... and you can recolor the whole artwork in one shot
EDIT: But the colorblindness settings on the colorschemedesigner are really cool!