Marc Kreiner's first idea was to deliver specialty rental vehicles to high-end cus-tomers. When he discovered that an overwhelming majority of those movers and shakers requested cellular phones with their wheels, he quickly jump-started company concept number two: a cellular-phone-rental company.

Though he was just 18 months -- and $10,000 -- into the vehicle-rental idea, Kreiner didn't hesitate to develop his second brainstorm. He spent $4,000 on a half-dozen cellular phones and created Road & Show Cellular in January 1991.

When the first-year revenues of Kreiner's new company outstripped those of his car operation ($3 million), he knew he'd made the right decision. With anticipated 1992 revenues of $22 million and 125,000 annual rentals, 20 offices scattered across the country, and more than 10,000 cellular phones, the Marina del Rey, Calif., start-up is now the nation's largest cellular-phone-rental company.

-- Alessandra Bianchi