So then, there's this:
Halfbike | Halfbike | The compact and light standing bike, anywhere with you!
I believe I once saw something like a seat-less and seatpost-less two-wheel, pedal powered scooter in one of the Encycleopedia issues, but it was rear drive and had a traditional headset/front steering setup going on.
I'd often imagined taking one of the older Dahon bikes, the one with the handlepost to top tube supports and merely deleting the seat posts and saddle to effect the same basic idea.
But then this just popped up when a friend posted it to FB. Three wheeler with rear steering that owes more to a skateboard truck than a bike. With a stand-up design like this, I don't see an easy way to turn it into a front-drive two-wheeler, even with some kind of crazy swing-bike/Flevo-bike geometry.
I like the idea, but am less than impressed with the folded dimensions. Would love to try one out...