Save the environment and burn calories at the same time at this compact 3,000-square-foot gym: It runs on solar power as well as on patent-pending machines that generate renewable energy as you exercise on them. New members get a free fitness assessment, a 30-minute massage, and a swipe card that allows open-door access to the club from 5:30 a.m. to 11 p.m. daily. Plus, for every hour of electricity you generate, you gain $1 toward gift certificates at local businesses. Its carbon footprint is already 85 percent less per square foot than that of other gyms. "I always get a good workout, and I'm inspired to walk there and back to save gas," member Tiffany Morrison says.