A bitter billing dispute with her electric company changed environmentalist Keya Chatterjee's life. Battling Pepco over charges for electricity at her Washington, D.C., row house in the dead of winter six years ago, Chatterjee eventually just ordered the utility to shut off the power. She and her husband lived in the dark and cold for a few months, an experience that convinced them that even when they turned the lights back on, they could use less power. They went on a strict energy diet, one that has only increased since having a baby two-and-a-half years ago. "Getting mad at Pepco was like a gateway drug to sustainability," Chatterjee said. "Then we started getting rid of everything."