cholden and others have posted this many times as a good color picker.
http://www.webhelps.com/help/colorscheme.html
I thought though, I hate bookmarking things like this, not only am I giving someone a reward for those stupid ads, but what happens if I come to rely on this and then the site goes down. What happens if I don't have net access?
Also I just hated the adds below it.
So here is a stripped down, ad-less zip file containing everything you need to use the color picker locally. Tested in firefox.
www.poopinmymouth.com/net/pcount/color_picker.zip
Replies
http://colormatch.dk/