Then there are electric/manual powered bikes of all kinds of variations.One guys homebuilt........

http://www.youtube.com/watch?v=Fkuj46N_lk8

Recumbent 3 wheeled bicycle with full suspension, rear hub electric motor, lithium ion battery pack and full shell velomobile. Sits high like car and can go up to and more than 65 miles per hour or 85 kilometers per hour.
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Now he talks about powering it down to 200 watts....if you had 2 of these foldable 136 watt solar panels from unisolar (craigslist is your friend) If you got 5 hours of sun a day while parked you could drive it 5 hours at night,now not sure what 200 watts will do on the thing,but it will do something for sure....how cool is that????

Or even pack a couple of these for your electric assisted bicycle?

They are PVL-136... 18 ft long. 15½ in wide. 0.16 in thick. 17 lbs.