This is something I've been throwing around for a few years--ordered the main components tonight. Should be ready to start building in a couple of weeks--damn hong kong shipping times. The controller supports 32 channels, at 500ma each. Most LED's are 20ma so that's 25 LED's per channel maxed out--but since I'm using RGB LED's, that's 3 channels to power even a single RGB LED. I can make 10 "modules" of 25 led's each--thats alot of LED's though.
x50 10mm RGB Common Anode LED's
Some kind of U or h channel steel stock
4 conductor cable--might just use cat5
Resistors, tbd based on psu and number of led's per module.
So I got a couple of these usb missile launchers off Woot! a few weeks ago. They are pretty neat so long as you disable the lame SFX, toss a webcam ontop and remote desktop in and screw with someone baaaaad. I have one of these in my shared office at work, it's scares the hell out of people when something shoots at them for no appearnt reason...