"Erowid is a small not for profit organization dedicated to studying and providing information about humanity's never-ending search for meaning and spirit. We recognize that every individual is on their own path and that no single path is best, or even functional, for all. History shows us that regardless of social or legal controls, people will follow their own individual paths in this search for meaning. It is extremely important for information to be freely available about different techniques, practices, methods, and lifestyles, whether traditional or unconventional."(1)
The Vaults of Erowid host and record tremendous amounts of information regarding entheogens. The information they present on commercially available pharmaceuticals is somewhat limited, but there isn't a better place on the web to find FAQs, images, and reports of experiences with herbs and chemicals.
Erowid now hosts the information on entheogens which was once found on hyperreal(www.hyperreal.com). On a similiar note, large sections of TiHKAL and PiHKAL are hosted in the library
(1): http://www.erowid.org/about.shtml#intent