>The thing is efficient because it doesn't let
>you use it inefficiently.
Actually, just like in the car, if you choose to use if inefficiently -- you can. All you have to do is rock forward and back and the effect will be the same as alternately applying gas and brake.
>First, this thing is accident-prone... some kid
>jumps out in front of you, you hit the stop
>button (or however that works,) and this
>thing actually speeds up.
You don't use a "stop button". The way it works (when you want to stop) is you just lean back (imagine pulling back on the handle bars like reins). So, rather than it speeding up to get underneath you (as in your example), it is forced to *slow down* to get underneath you. The further back you lean, the faster it has to slow down and at some point (if you don't stop leaning back) it must go into reverse to keep you from fallng off.
JB
PS: I still say it has limited uses.