I like to use the Dream Machine for altered states...

http://www.noah.org/science/dreamachine/

The above link shows you how to build your own. The idea is similar to the brainwave generator, but it's a little more organic and hands-on. Grab an MP3 of a Hemisync Holosync or Theta mediation, loop it on your computer, and let this light machine do the rest. I use mine almost daily.

The man who invented the Dream Machine (Brion Gysin) is an amazing source of inspiration...an artist in every sense of the word.