I've just about finished a flash-based color picker called "PaintersWheel" that, shall we say, coincidentally, closely resembles Painter's color wheel and triangle.
It works only with CS4 (which supports the flash technology its based on).
I'm looking for beta testers ASAP.
In particular I want to test a variety of configurations (Mac, XP, Vista, 7, 32, 64 bit).
If you are interested, send me a private message and your system specs.
When it's released (within a couple weeks, I think) it will be freeware (asking for small donation to make me feel loved).
Thanks for the help!
Attached it is a screenshot with it attached to Photoshop's color panel.