TerraCycle <http://www.terracycle.net/>  turns waste into profitable products. It’s an awesome business that embodies the idea of a sustainable economy, as it creates a market for products made from trash. TerraCycle began with two freshmen at Princeton University, Tom Szaky and Jon Beyer. Basically, they sold worm castings (fertilizer) in a wasted soda bottle. They took food waste from their school dining hall, fed it to their friendly worms, and voila, a commodity to be sold. This packaging of dining hall-sourced fertilizer in junk plastic bottles continued to sell, and eventually TerraCycle fertilizer was being sold at Home Depot and Whole Foods. Now, TerraCycle has expanded to include purses, bags, fences, and boxes–all made from trash.