Add heaps of red worms to mountains of raw, rotting garbage. Then collect the worms' feces, brew it into a liquid, and squeeze it into a used soda bottle. Sound like a twisted fourth-grade boy's concoction for messing with his sister? Not quite. Rather, it is TerraCycle's recipe for success -- as a booming, eco-friendly fertilizer business. We're not doing this to help save the environment," said co-founder and CEO Tom Szaky. "We're doing this to show that you can make a lot of money while saving the environment." It does that not only by avoiding excess waste, but by embracing others' throwaways -- from the organic material fed to its hard-working worms, to its used plastic packaging, to the once discarded desks and computers in the firm's Trenton, New Jersey, headquarters. The nonprofit environmental group Zerofootprint recently recognized TerraCycle for having "net zero" negative impact -- the first consumer product to earn that distinction. This unique business takes its cue from Szaky. The Princeton drop-out, born to Hungarian parents and raised primarily in Canada, said he doesn't consider himself an environmentalist, admitting he doesn't eat organic food or drive a hybrid car. Many of the breakthroughs came out of necessity, conveniently married to the pro-environment, anti-waste cause. The two core components are worms -- which eat, excrete and procreate freely -- and similarly cheap, all but omnipresent organic waste. When short on cash, TerraCycle decided to place the liquid fertilizer in used, plastic soda bottles scooped off the streets instead of buying new or recycled bottles.