Could that Maxlite at your side be a musical instrument in disguise? With up to 9 audience participants, viewers of the RGB project can control sound and visuals using colored flashlights, in a performance installation by Tomas Dvorak (CZ), Alessandro Capozzo (IT) and Matous Godik (CZ). The team used the free PC-only software EyesWeb, passing data to Macs running Max/MSP for sound and Processing for visuals. If you wanted to do something like this, EyesWeb would be a good place to start; it can track the movement of specified color(s) through a live video signal. There are other options, too; watch for an upcoming how-to on camera input in a print story by me (can’t say where yet, but I’ll let you know when I can).