As far as personal mobility concepts go, the Treadway Mobility system is one of the most compact. You simply slide your feet into them, shoes and all, and go. Most exciting is that Peter Treadway, designer of the skates, has submitted them to the James Dyson Awards competition.
If the King of Vacuums enjoys the idea, Peter Treadway's vision of the future where everyone zips around as opposed to walking could actually come to be. You don't have to always wheel, though. The skates lock in such a way that you could also, say, ride a bike. It's all controlled by a unit you hold in your hand, which will have you cruising along at up to 10 mph.
Now, sure, we could all dash an idea like this, designed for that "last mile" after you get out of your car or off a bus, for killing the small amount of exercise the average person gets. Still, as someone who has to walk up a long, long hill every day, I wouldn't mind a set of wheels for when I need a little extra boost.
Check out the Treadway prototype in action in the video below.