(FORTUNE Magazine) – IRWIN JACOBS By pioneering the commercialization of (and snapping up a load of patents for) the digital wireless standard CDMA, Qualcomm CEO Jacobs, 69, has conquered the North American market for cellphone chipsets. Now he's focusing on Asia and South America.

LOWRY MAYS Over the past seven years Clear Channel founder and CEO Mays, 68, has amassed a $26 billion empire that includes 1,200-plus radio stations, reaching more than 100 million listeners a week. His massive consolidation, complain critics, has made the airwaves all around the country sound the same.

BILL MCGUIRE The CEO of UnitedHealth Group, 55, transformed a $600-million-a-year regional HMO into the nation's largest health-services company, with $25 billion a year in sales. UnitedHealth now counts one in six Americans--50 million--as customers.