Smug about your 65 mpg Prius potential? Don't be. A little car from up-start Riversimple looks set to deliver the equivalent of 300 mpg, running on hydrogen and utilizing a network of small fuel cells to power four motors, one per wheel. The recently unveiled prototype manages 240 miles on just 2.2 lbs of hydrogen, has a top speed of 50 mph, seats two (reasonably) comfortably, and looks a little like a smiling, new-age Citroen 2CV -- but will hopefully be a more enjoyable to drive. That consider
