HPPD: Hallucinogen Persisting Perception Disorder
Information, treatment, and forums for sufferers of HPPD (Hallucinogen Persisting Perception Disorder), also known as flashbacks, which happens to some users of psychedelic drugs.
http://www.stormloader.com/hppd/

Trip Magazine
A mainstream publication for about psychedelics.
http://www.tripzine.com/

Erowid Psychoactive Vaults
Information on entheogens, psychedelics, and hallucinogens including traditional, spiritual, and responsible use, chemistry, effects, experiences, images, research, legislation, media coverage, bibliographies and links.
http://www.erowid.org/psychoactives/psychoactives.shtml

Ask Dr. Shulgin
Information about psychedelics, entheogens, empathogens (MDMA, Ecstasy), from a pharmacologist and chemist.
http://www.cognitiveliberty.org/shulgin/

Serendipity: Psychedelics
Articles on psychedelic mushrooms and DMT (with field notes on DMT experiences); LSD and Ketamine trip reports; preservation of dried psilocybin mushrooms; links to other documents concerning psychedelics.
http://www.serendipity.li/trypt.html

HPPDonline.com
Information and message boards for people with Hallucinogen Persisting Perception Disorder (flashbacks).
http://www.hppdonline.com/

Cluster Busters
Information regarding the use of hallucinogenic substances for the treatment of cluster headaches and other vascular headaches.
http://www.clusterbusters.com/faq.html

Status of Ololiuhqui in Mexico
Describes picietl, peyotl, teonanactl, and ololuihqui, four divinatory plants. Article by R. Gordon Wasson.
http://pages.prodigy.com/GBonline/liquix.htm

Tryptamind
Resource on psychoactive, psychedelic and hallucinogenic plants and the pharmacological effects of their active chemical constituents.
http://www.tryptamind.com/

The Psychedelic Library
Menu of articles, research papers, books, and essays on LSD, peyote, psilocybin, and the use of psychedelic drugs in research, therapy, religion and personal growth.
http://www.psychedelic-library.org/