MAKE's Bre Pettis has a video about making a sound-and-light brain machine (which is featured in Make, vol. 10)
This weekend, learn how to hack your brain by making Mitch Altman's Brain Machine! It flashes LEDs into your eyes and beeps sounds into your ears to make your brain waves sync up into beta, alpha, theta, and delta brainwaves!
Mitch invents cool things that make the world a better place. He's well known for the TV-B-GONE and this brain machine is his latest project. One of the cool things about this project, is that it builds on an open source project. Mitch used Lady Ada's open source MiniPOV and switched out LEDs and added new capacitors and resistors and then rewrote the firmware to make it into the brain machine. It's super cool when people make hardware open source so that others can work with it!
