Oreilly is making available a free online course dealing with Processing and Arduino combined to produce a video mixer/audio visualizer. Led by instructor Joseph Gray, the course takes place Fridays @ 10am PT February 25 & March 11, 2011. Each session is 120 minutes. You may view the course live online for free; thereafter, to view the video there is a charge.
The course uses a projBox which is a collection of potentiometers, switches, LEDs, an Arduino and breadboard which you can build yourself in time for the course.