Title: VP, Search Products and User Experience, Google
When Marissa Mayer joined Google in 1999 as its first woman engineer, she says she gave the startup a 2% chance of succeeding.
Now, Mayer not only directs the look and functionality of the $14 billion tech giant, she's also behind more than 100 products, including Google Earth and Google Chrome, the company's recently unveiled web browser and operating system.
NEXT: Jan Fields