A Need for Speed There's plenty of opportunity in the multibillion-dollar NASCAR scene.

If you're going to be called America's fastest-growing sport, you'd better have speed. Fortunately, NASCAR has plenty of it. Drivers race around the track at over 200 mph in front of swelling grandstands while the business world tries to keep up. Companies like The Home Depot and FedEx have snapped their harnesses tight in preparation for the ride.

Where's the opportunity if you're not a billion-dollar giant looking to sponsor a race team? All over, according to Scott Warfield, PR manager for the Charlotte, North Carolina, division of NASCAR. First, he points to the growing legion of women who follow NASCAR. In fact, 42 percent of its fans are female, according to an ESPN poll.

In 2004, Lisa Heros was attending her first NASCAR race with some female friends in Las Vegas when she noticed a market opportunity. "We couldn't find anything to wear [to] the race," says Heros, 28. "So I made shirts for us to wear, and people kept coming up to us [wanting] to buy them."