In the Future, We Will All Drive Pacmen
For the ultimate in zero-emissions driving, forget hydrogen and embrace air: Compressed-air cars are real, and the French company MDI have been trying to get them on the road for years.
Their newest entry in their air-car lineup is the AIRPod, which uses bright colors and a (kinda) futuristic "pod" design for their zero-emission buggy that can approach a kid-friendly 44 miles per hour. (According to the MDI website, in France, children and unlicensed adults can drive in city traffic as long as they don't top 45 mph. I kid you not.) The cute-as-a-button AIRPod has a drive-by-wire joystick instead of a steering wheel, which means those Galaga skills will come in handy when parallel parking.
Though the AIRPod is more suited for congested European cities than staring down a Ford F-350 on the 405 freeway, the American subsidiary of MDI, Zero Pollution Motors or ZPM, plans on introducing a compressed-air family sedan to the US market in 2010.
MDI/ZPM’s compressed-air technology is pretty much self-explanatory: Use an electric compressor to squeeze a lot of air into a small, super-strong carbon-fiber tank, and then use it to drive an engine. (See this inadvertently goofy animation for more details.)
While the technology is still in its adolescence, with huge investments from the likes of India's Tata Group, it'll grow up soon.