Brion Gysin, lifelong collaborator of William Burroughs and guiding force in his cut and fold experiments also invented (along with his friend the mathematician Ian Sommerville) the Dreamachine. A dreamachine is a kind of meditation device using flickering light emitting from specific shapes to allow for a mathematically calculated rate of flicker. The device is "viewed" with closed eyes and apparently allows one to achieve an oracular dream state - sounds good to me!
The Dreamachine can be made from a cylinder of card with slits cut in the sides, it is then placed on a record turntable and rotated at 78rpm or 45rpm with a light bulb suspended in the centre of the cylinder. "This spinning, flickering cylinder was designed to affect the alpha rhythms of the human brain, allowing access to one's inner visual capacities. The first object-kinetic sclpture to be viewed with your eyes closed. Gysin spoke of flashes of memory and 360 degree visions with the clarity of projected film after extended use."

Gysin's Dreamachine plans are available to downlaod from Ubuweb here (at the very bottom of the page). Obviously not suitable for epileptics.