— Marissa Mayer, vice president of search products and user experience, at Google , which was incorporated 10 years ago this week. Mayer was a 23-year-old Stanford grad and specialist in artificial intelligence when she met co-founders Larry Page and Sergey Brin in April 1999 and Google had fewer than 20 people. The two brainiacs interviewed her in a makeshift office over a ping-pong table and hired her as Google’s first female engineer. In a way it was crazy, she told me last week when I sat down with her at Google. But her best decisions up to then, she explained, had involved stretching herself, even when she felt not quite ready, and associating with the smartest people.

To Mayer, organizing the world’s information was a compelling challenge–more so than her 13 other job opportunities, which included working at Oracle , McKinsey, and Toyota in Japan. A wise risk, it turned out to be indeed, as Google has been the fastest-growing technology company ever, with $16.6 billion in 2007 revenues and a current $139 billion stock-market value. Mayer, now 33, oversees thousands of engineers and product managers and shapes the design of Google’s vast array of products.