It's the American dream--start a company, make a fortune, and retire early. But to become multimillionaires in their twenties, as Google founders Larry Page and Sergey Brin did, boggles the mind. All they did, after all, is come up with a better way to search for things on the Internet, right? Only in part. No company achieves a market value in the range of $172 billion (in early 2008) based on a single good idea. This new entry in the Corporations...