International Trepanation Advocacy Group (ITAG) http://www.trepan.com/

The Foundation to Further Consciousness Gives information about various techniques of expanding consciousness and does research into the physiology underlying it. http://www.brainbloodvolume.com/

The International Trepanation Advocacy Group Information on trepanation, the art of drilling holes into people's skulls. http://www.trepan.com/

Trepanation Guide An indepth source of information on medical and historical aspects of this ancient surgical procedure. Includes references and citations as well and advanced reading suggestions. http://www.trepanationguide.com/

Trepanation Trust provides scientific information, images, and articles about the practice of trepanation, including people who've done it themselves http://www.trepanation.com/