Inventors and Their Inventions

William Walsh
The Green Box, an environmentally friendly pizza container
The top half of the Green Box Pizza is perforated to split into four plates, while the bottom half folds up into a container for storing leftovers. Inventor Walsh traces the idea of it to his college days, when he and his housemates would eat pizza and nobody used plates. One time, he tore up a pizza box and handed out improvised plates. His housemates were amazed, but he dismissed it. "I thought it was standard operating procedure," he says. Ten years later, people were similarly amazed when he tore up a pizza box at a friend's daughter's birthday party. Now equipped with the wisdom of a degree in business, he decided to start his own company.

• 50 Best Inventions 2009