Re: You missed one...
Adult scooters of any kind, electric or not. It's an infantile and inefficient mode of transport.
I was down in that London the other day and saw some hipster type guy scooting around on a bizarre contraption...kind of Segway-ish, but just one wheel, and no upright. I suspect that he thought he looked the bees knees....but from the look the faces of everyone that he passed by he was more like the bees rectum