Here’s a new idea I added to the idea section:

Balancing Scooter — August 2013
What if I could merge my putt-putt stander-scooter with this?:
John leans forward in the stander and it goes forward.  Leans to the side and it steers to the side.  It’s so compact.  John would only take up about as much room as a person does.  A definite space saver when in a house.  Wonder how it would do over thresholds or carpet.  Wonder if anyone could make it for me!