It's a one-wheeled, self-balancing electric skateboard called (appropriately) the Onewheel. You can't buy one right now. They've already shipped all of their first production runs and still have Kickstarter backers' orders to fulfill. After that, though, they might make one for you -- if you come up with a deposit of $500 against a total price of $1499. Plus shipping. This may seem like a lot of money to some people, but enough folks have found it reasonable that Onewheel has sold out not just its first production run but also the second one. Their Kickstarter success was nothing short of amazing, with $630,862 raised although their goal was only $100,000. Inventor Kyle Doerksen is the man behind Onewheel, but he's also one of the people behind Faraday Bicycles, whose flagship model costs $3500 -- and whose initial production run is also sold out -- which means there are people around who are willing to pay $3500 for an electric bicycle instead of putting a motor kit on a used Schwinn for a total cost of less than $500 (with a little careful shopping). Alternate video link.