Much like the monome, the Tinct has a couple of auxiliary analog ports (although only two, and no support for rotary encoders as of yet). Here I've modified the 64life Chuck program to have some colour cycling, and to set the speed from a potentiometer (aka a knob) attached through one of these ports. I have it doing my favourite test, a simple oscillator, and you should hopefully be able to see some colour cycling, too.
I still need to get around to writing software which actually uses the multicolour capability for something interesting, plus I need to design and build a PCB to replace the mess of breadboarding, and of course a case, but the hard part is over!
The Tinct project is an Arduino-based clone of the monome, with the addition of full colour LEDs, each capable of being set independently. For my details, check out http://upnotnorth.blogspot.com/2008/03/octinct-is-up-and-running.html
2010 update: that Blogspot page is long abandoned. For the latest on this and (mostly) other projects, check out my new site at http://upnotnorth.net.