Paul Stamets on 6 ways mushrooms can save the world: http://www.ted.com/talks/paul_stamets_on_6_ways_mushrooms_ca...
This talk is not about hallucinogenic mushrooms. It really opened my eyes to the awesome potential of fungi, and how this potential is largely ignored because of the connotation to "hippy" and "drugs." Fungi is just generally misunderstood. I was absolutely amazed at how thorough these clean-up jobs were, at how well the fungi consumed, not only the waste, but the toxins in the waste.
Stamets recently wrote his fungi take to cleaning oil spills: http://www.fungi.com/mycotech/petroleum_problem.html