If boundless enthusiasm and unlimited energy defined power, Richard Edelman would undoubtedly top our list. He is a multi-tasking dynamo who keeps all 3,700 of his employees on their toes while simultaneously empowering them with the freedom to be innovative and creative. Even Edelman's detractors grudgingly admire the way he has grown his family firm into a global behemoth that can compete with the largest of the holding company agency networks. In 2010, Edelman consolidated its claim to be the biggest global PR agency, with billings in excess of $530 million bolstered by four acquisitions and a slew of new accounts. You can be sure Edelman's ambition does not stop there.