>brain machines<

Even if lucid dreaming and out of body experiences could be associated to some trendy (and often expensive) new age stuff, the theory beside brain machines is really simple and solid.
 
After a bit of exploration on psycodynamics, binaural waves and brain consciousness levels, I've built my own simple electronic dream machine.
 

It consists of a main VCO that drives a couple of leds mounted on sun glasses. Feeding the VCO with calibrated voltage ramps you can generate fadings between beta and alpha waves or slower and deeper frequencies.