So, I saw Cameron B's Electrosketch project at dorkbot tonight. Really, really cool stuff. Inexpensive, but really engrossing and with a lot of depth to it. A Sharpie with an infrared LED is tracked by a hacked webcam that has its IR filter removed and a piece of 35mm exposed film put in its place. The computer, running proce55ing, locates the pen and generates vertices in OpenGL that form strands. The strands formed these great different shapes depending on the direction in which the vertices were generated, which was controlled by a custom box hooked up to serial.