PayPal

Education: Bachelor's degree in economics, Hamilton College, Clinton, N.Y. Residence: Paradise Valley. He left PayPal after it was acquired by eBay Inc. in 2002 for $1.5 billion in stock and moved to Paradise Valley last year. He commutes to the Bay Area to help former PayPal colleagues run Clarium Capital Management LLC, a hedge and venture-capital fund. The PayPal team's original business idea in 1998 was to create a global currency system, Selby said, but they soon realized they needed something more concrete. They spent nine months developing the technology and encryption to beam money from one Palm Pilot to another.

"Then it finally dawned on us that there are a lot more e-mail addresses than Palm Pilots in the world, and we decided . . . maybe we should shift our business model," he said.