David Sun

Came to U.S. in 1977 from Taiwan, became chief engineer for Alpha Micro. Cofounded Kingston Technology with John Tu in 1987; today nation's largest privately held computer memory firm. Company's USB flash drives and flash cards grace cell phones, digital cameras, MP3 players. Estimated sales up 22% to $4.5 billion in 2007. Pair started memory-chip outfit Camintonn 1982, sold 4 years later for $6 million, then formed Kingston. Sold 80% stake to Softbank for $1.5 billion in 1996, bought it back for just $450 million 3 years later.