Throttle-less Electric Bike
 

http://www.metaefficient.com/bicycle....html#more-976

It uses a torque sensor on the pedals to determine how much 'throttle' to apply. The harder you're pedaling, the more assist it provides.

I suppose if I were to spend 2 grand for a bicycle this would be a serious contender.

the curi tec bike does the same thing and costs closer to $700 last I looked, I have plans to build one for my electric bike when I get time then just keep the bike in high gear all the time.