I used to jog home from work some evenings when living in Perth - CBD North shore to South shore accross the Narrows Bridge cycleways/paths.

It was never unusual to be overtaken by cyclists or other runners - especially when you're as slow as me. But every night some pr!ck in a suit would go past on one of those things, with his brief case across the handlebars.

Had to chuckle. Although the Perth foreshore is graced by many entertaining characters, such as middle aged wrinkly women 'power walkers' in pink track suits, led by a white poodle fresh from a shampoo and set (the poodle that is), this took some beating. Least of all, because it was one thing for this guy looking a tw@t, but at least others who looked stupid were getting some exercise.

So I suppose the answer to your question is, yes, people do use these things. This guy's was very quiet, so I guess it was battery powered.