A quick Processing sketch which uses my dilapidated webcam to follow the region of highest RGB value around the screen, then uses the coordinates to send MIDI notedata and MIDI-CC values through a virtual MIDI device to a basic and nasty filtered monosynth in Max/MSP.
A nice feature which compounds the baffling uselessness of this endeavour is that when you click on the screen, it saves out two jpg files - one a grab of the unweirdified webcam stream and one a wysiwyg screenshot.
I'm fairly positive it wouldn't look as mental if my webcam wasn't so awful, so that's a pretty cool side effect.
Captured with Debut Video Recorder, this lovely little freeware app. Clearly it was designed for running off keepsakes for 'personal use' during porn camshows, but it's also very useful for this sort of thing :)