Yesterday I saw a colorwheel used in photoshop by an artist Named Nox at massive black. You can get the colorwheel by purchasing the dvd, but who wants to do that? Photoshop should have one anyways but for some unknown reason doesn't. Well I did a quick search and found Spencer Goldade posting two excellent ones on his site... monkeyslunch.com
Anyways, it's actually just swatches arranged into a circle, but it works great! Just make sure your swatches are set to 20 wide (just scale the window) or it won't appear as a circle.