Trikke Tribred 36v Lite: $1,299
As Trikke Tech President and CEO, John Simpson, told Discovery News at CES, "Originally, [co-founder Gildo Beleski] was looking for something stable just to bomb hills. He had no idea that this design would propel using your body. And now that the motor and battery technology has gotten so good, it was just a natural to plug them into our frame system."
That need for downhill stability led to a three-wheel design, which eventually lent itself to either a great workout or just a great ride. To exercise the upper body more, push off with a simple leg pump or the cooler looking rock forward method. Weave the handlebars back and forth until you build enough momentum. Then evolve the quick swiveling into a rhythmic swaying motion that mimicks carving like a downhill skier.
Or if like a certain lazy reporter (see video below) you're looking for the less strenuous version, twist the hand throttle to let the 36-volt battery and 180-watt motor give you that initial push. And after that jumpstart, rock it yourself the rest of the way. Or some combination thereof.