This link was sent to me by my wingman and I thought some of you would try it:
Science: Headphones Playing White Noise and a Ping Pong Ball Let You Trip Sans Drugs
whoa, Steve dude, that is totally trippy man. 
Well this is enough to make you curious. 
Sounds more like a placebo psychology experiment to me. If they will themselves based upon the premise of the experiment, then they will.
You can also try holotropic breathing which is basically hyperventilation. You will probably puke though. The seminal book on the subject is by Stanislov Grof. In an earlier thread it turned out our very own Tacitus sat beside him on a train trip. That is some life he has.