A nice introduction to Permaculture that's also an overview of the Permaculture Congress held in Brazil a few years ago that's also nice examples of Permaculture operations in practice. For example a tour of collecting the feces from pigs and sheep into a pond, that goes into a biodigester, to produce natural gas, that runs a turbine to generate electricity, and the effluent from the biodigester becomes a pond in which they grow water hyacynth's, that are essentially weeds which can be used as feed for the pigs.It starts with a quote from Bill Mollison talking about how teaching people to grow their own food is subversive. It teaches them independence giving them freedom from the system. Hence it's a kind of revolution, but a quiet one because it's just people gardening. Permaculture - A Quiet Revolution from Spread Knowledge on Vimeo