energy | Ellen Gaughran | plant food | fight disease

None of this would mean much if the resulting plant food, though ingenious, were ineffective. But judging by sales - which have grown from just $70,000 in 2004 to $1.5 million in 2006 to $2.5 million for the first half of 2007 - plenty of consumers think it works. Szaky insists that the 70,000 microorganisms living in it are what make it so powerful; picking up a bottle, then, means buying something that is, in effect, still alive and kicking. "These microorganisms help fight disease; they help bring nutrients to the roots - it's like an ecosystem," he says. "One of the big problems people have, especially in America, is they douse their garden with chemicals, which wipes out all the bugs that live in your garden. But the bugs actually help your garden."

SZAKY COFOUNDED TerraCycle in 2002 with one of his Princeton roommates. With the company's growth has come a maturation. What started as little more than a collegiate lark has slowly evolved into a more serious enterprise, albeit one whose founder wears a uniform of a baseball cap and jeans and whose employees at the company headquarters in an inner-city area of Trenton never don a tie. As the business has added staff, Szaky has brought in people with a lot of experience at large corporations. His leadership style has also evolved, although Ellen Gaughran, TerraCycle's head of human resources, says one of the bigger challenges for the company's more seasoned executives is to keep Szaky focused. "Because of his entrepreneurial energy, he wants to do so much, and we have to rein him in," she says. "He wants to produce 25 new products next year. Well, it's almost physically impossible to do it. It's about harnessing his energy and passion, because he's got so much of it."