When Google hired Marissa Mayer
in 1999, she was the company's 20th employee
and its first female engineer
. She went on to become the person responsible for designing and developing the attractive and easy-to-use search interface, and has launched more than 100 features and products on Google. She oversees many of Google's most-used features including Google Images, Google Maps, Google Earth, and Google Books. Mayer's work may be behind the scenes, but many recognize her power and her worth; Fortune named her one of the 50 Most Powerful Women
-- at age 33, the youngest ever to make that list -- and Newsweek cited her
as one of " the next generation of leaders in their fields." The ultimate test of her influence? Google her. You'll see half a million results.