Originally posted by Corazon
the holosync cd's contain specially designed sound waves (not exactly sure of how the science of that works) that are embedded in soothing music tracks
Ah, you must be refering to the binaural beats. There's a free app out there which you can download and customize to your liking, then export as a sound file and use (no purchase necessary ). The application is called BrainWaveGen (follow above link).

I will go ahead and endorse the product even though I stopped using it (out of trying not to become dependent on it -- and also too lazy to put the new pattern I created on my iPod! ) The link will explain how it works, but based on the theory that if your brain is exposed to a particular frequency (delta, theta, etc), it will "adjust" itself and "tune" itself to that frequency. By programing when and for how long you play these frequencies you can essentially control your sleep pattern. It's not perfect, but I notice the shift in alertness/drowsyness as frequency changes. If anything it really did help me fall asleep faster (which I normally have trouble doing).