Recyclebank

"We help communities and individuals realize a world where nothing is wasted," says Recyclebank CEO Jonathan Hsu, whose firm asks its 3.1 million users to recycle (duh), and is expanding into programs to reduce energy use or promote walking and biking. Its requests are gamified: Actions earn points, redeemable at retailers such as Best Buy and Walmart. A new deal with Waste Management will bring Recyclebank to the trash king’s more than 20 million North American customers. One thing piles up: Recyclebank’s revenue reportedly doubled in 2011.