http://www.bwgen.com/
This is a shareware program called "Brainwave Generator" that I have played around with with some success. It allows you to entrain the general wave patterns in the brain to specific frequencies. I have found, for example, that a pattern of 6 Hz reliably vanquishes foot dystonia ("curly toes") in less than ten minutes. Sort of a poor man's DBS. A lot of room for research.