A fascinating book on states of consciousness

This is a great book describing twelve states of consciousness, including advice on how to enter some of the more exotic ones. Personally, I think Stephen LaBerge (the leading researcher on lucid dreams) is a bit of a flake, but from what I can tell his science is sound. Paul Ekman also has a mention, though his research is rather peripheral to the topics in this book. I have been a huge fan of Ekman generally for years. I follow the blog of one of the "natural lie detectors" identified by Ekman's research, Eyes for Lies. Also recounted is the story of the Dream Machine's inspiration by Brion Gysin's passing down a tree-lined lane and experiencing alternating light and dark at the approximate frequency of the brain's alpha-wave rhythm. This was a familiar story to me; my old upstairs neighbours had a copy of the original book Warren cites, and they had a homemade Dream Machine in their apartment. From what I understand, they never actually managed to induce any hypnagogia with it though. Nevertheless, I am very interested to try some of the techniques outlined in this book.