I recently bought an electric skateboard (kaly board for those so inclined). Commuting on one of these to work costs me about 20 cents in electricity. I can only do it when the weather is nice though, right now the cold just cuts through to my bone.
Electric skateboards are insanely fun and after purchasing one I became convinced these things and (mostly) scooters are going to become ubiquitous in cities where the climate allows it.
I know, it really feels like the future. One day I hope we're all traveling around on electric scooters, skateboard and bikes.