While surfing around I come across this extensive but very interesting site.
by the Behavioral Neuroscience Group of Laurentian University in Sudbury,Ontario,Canada.
http://www.innerworlds.50megs.com/earthfee.htm
If you scroll to the bottem of this page,look under Home Page,near the bottem you will see "downloads" there is some interesting free software there. To the left of Home Page; is Shakti-Magnetic Brain Stimulation.
If I properly understand what they are saying, by stimulating the brain with a very low magnetic wave; they are able in induce on a regular basis
various altered states of consciousness including lucid dreaming,astral projection,visions,etc.etc. If you take the time to read over this site- this machine and what it does has been studied extensively in the lab at the university. The following link provides serious academic references for many of the studies that provide the foundation for this class of technology.
http://www.innerworlds.50megs.com/Persinger_pubs.htm
Somewhere in there I saw a site where you can buy the magnetic stimulators.They run off your computer using windows. The cheapest model was $70 canadian probably about $50 US. I found the comments by the study group the most interesting. While you experienced these altered states, you never knew thich one you were going to get.