What color scheme tool do you use?

It is often difficult to pick good color combinations for a web site design.  What tool do you use to help you find good colors that go well together?  In my case, I have a logo that was provided to me, and I want good colors to design the site to go with this logo.  I'm looking for a tool where I can feed it a color, and then it outputs two other color that is supposed to go well.  I'm also looking for a tool where I feed it a hex color code and it shows me this color on the color wheel.  Once I know its location on the color wheel, I can pick its complement or its tri-color scheme.

check this thread: http://www.webdigity.com/index.php/topic,2136.0.html

check out this little tool: http://www.colormatch.dk/ (IE only but others have made enhanced versions of this program)

nice tool

don't forget to read this:

A lot of enthusiastic people around the World have not only made it more compatible, but also added even more features. Google will guide you to them!
http://www.google.com/search?q=colormatch+5k

I like this version:
http://hlrnet.com/colormatch/index.php

(works in FF too)