Susan Wojcicki may be best known to the outside world as the person who rented her Menlo Park, Calif., garage to Larry Page and Sergey Brin, then a couple of computer scientists looking to build a better search engine. Inside Google (she was employee No. 18), however, she's known as a prescient thinker who has figured out ways to extend Google's reach. She got her start licensing Google's search engine to other sites, then spearheaded AdSense, which uses Google technology to place ads on third-party websites. Today she oversees all the company's ad products (translation: nearly all its revenue) and product management, and recently became responsible for engineering -- a powerful portfolio that is sure to lead to more ways for Google to sell ads.
Wall Street is buzzing about IPOs from LinkedIn, Groupon, and Zynga. But what about those small, innovative companies looking to cash in? Fortune spotlights ones that show lots of promise.
