Mind Hacks has a fascinating link to, and post about, a collection of videos of trance states at Neuroanthropology. The Mind Hacks article offers further links of interest, so you can spend the night pondering how fragile your awareness is.
Equally fascinating is the cultural/mythical attachments which come along with the various trance traditions. From the methods of reaching trance states, to the beliefs of the people about what the trance state means, it’s a topic which you could dig into for a lifetime. Any reader suggestions for good literature on the various traditions of trance?