Has anyone tried these? What were your findings? The idea is that by listening to different wavelengths in each ear (through ear phones) you can 'entrain' your brain to that wavelength. Apparently this can be used for all sorts of things - sleeping aids, mood alteration, improved memory/attention, pain killing or even mimicking the effects of drugs. From my own experiments I found that some worked and some didn't, but it was hard to rule out a placebo effect.

Here's a link with some more information/downloads:

http://www.the-biomatrix.net/do-digital-drugs-work.htm