Mushrooms

Earth's Tongue
Supplier of spores and growing kits, including psilocybe cubensis, azurescens, tampanensis, and mexicana. Also sells prints and syringes.
http://www.earthstongue.com/

Fungi Perfecti
Specializes in the distribution of cultures, tools, and technologies for the cultivation of gourmet and medicinal mushrooms.
http://www.fungi.com/

The Hawk's Eye
Sells mushroom spores and offers growing guides and tips.
http://www.thehawkseye.com

Pet Fungus
Sells various species plus growth supplies, equipment, and books.
http://home.teleport.com/~lndscape/pf_home.htm

Psychedelic Cafe
Sells mushrooms, spores, kits, psychedelic spore trading, supplies and instructional CDs.
http://www.sporetradingpost.com/psychedelic_cafe.htm