The Christian Science Monitor has an interesting article on the potential for CNG (compressed natural gas): "From his suburban home in a wooded neighborhood once known for its shipbuilding prowess, Mann is crafting automotive gadgets for a future that many believe could help solve the nation's long-intractable energy woes – one fueled mostly by natural gas. During the past five years, Mann has converted more than 10 cars to run on compressed natural gas, in addition to gasoline, using a device he invented, the 'CNG Fogger,' which boosts the vehicles' mileage. Commuters in the Boston area have snapped up his cars from Craigslist as have CNG enthusiasts as far away as Wisconsin."
Of course, the article wouldn't be complete without discussing environmental fears ...