Dreamachine by Bill Lee

The Dreamachine is a device for altering the brainwave frequency of the user and putting it into an alpha state, at which point it begins generating waking, sober hallucinations and internal “movies”, on demand.

You could achieve the same alpha state after learning and practicing meditation, or by training yourself with bio-feedback machines, however the dreamachine offers you a fantastic light show and relatively quick alpha-wave production. People find that dreamachine therapy and other alpha-wave related therapy lead to decreased anxiety, overall calmness, increases IQ scores, increases in brain hemisphere coordination and overall intellectual function. All this without psychedelic drugs!

See Wikipedia article about dreamachine for more info!

WARNING: This software may induce PHOTOSENSITIVE SEIZURE (EPILLEPSY), If you or any of your relatives have a history of seizures or epilepsy, consult your physician prior to using Dreamachine.