[Lucius Cornelius Sulla]

Just what Americans need. A new way to avoid exercise.

What about the millions of people who can't walk more than a few steps (think substitute for walkers).

[Bloody Sam Roberts]

"What about the millions of people who can't walk ..."

I agree, that segment of society may benefit greatly from this, but look at it a little closer.
Many of the millions of people who can't walk also cannot stand, thereby making IT useless to them.
Many of the millions of people who can't walk won't stand (think of the motorized 4 wheel buggies like "The Lark" or others you see in malls and grocery stores).
Certainly Mr. Kamen cannot expect to get a decent return on his investment by marketing IT to the remainder.
He would need a large number of people, healthy and un-handicapped to buy IT.
You know, fat lazy people like me. =;^)

[syriacus]

What about the millions of people who can't walk more than a few steps (think substitute for walkers).

Exactly. People who now use canes or walkers when they have to walk any distance could find this helpful. Aging Babyboomers will eventually buy these. Just-In-Time invention.