Green cars have a come a long way - There are hybrids, pure electric cars and even those that run on biodiesel fuel. Now, there is the Imagine PS, a vehicle propelled by the ultimate green energy - Humans!

The car, the culmination of 40 years of hard work by Seattle-based engineer, Charles Greenwood, fits a maximum of four people, all of whom are required to work together to propel. The concept is fairly simple. Drivers crank up the small levers located in front of them, moving them backwards and forwards like a rowing machine and off they go! The best part is, they can face forwards or backwards or in any formation they like!

Capable of reaching speeds of up to 60mph on flat roads and 30mph on hills, the Imagine PS also has an electric, battery-powered engine for times when occupants need some speed, can't get a group together or, are simply too tired to exercise!

The human-electric hybrid is now available and can be ordered directly from the company's website. The price of the car ranges anywhere from $5,000 to $17,000 USD depending on options picked, which include an all-weather roof, a GPS navigation, air-conditioning and, a stereo that can be synched with your iPod - Now Fred Flintstone would have liked that!

And, Mr. Greenwood is not done yet - He has plans to a build a sedan, a sports version and even a foldable car that fits into a suitcase! To read more, or order your own human powered vehicle go to humancar.com.

sources:dailymail.co.uk, allcarselectric.com,