You may think that Marty McFly's hoverboard is still a fantasy. It is, but you can make a pretty rough approximation of it on your own today without it costing too much.
It's pretty straightforward, really. You just need a leaf blower, a tarp and a board. It takes some work, but it looks pretty doable. And the results look totally awesome. You might not be able to outrun Biff and his gang, but you'd still impress everyone hanging out in front of the old clock tower. I want one. [Jason Bradbury, Wonder How To via The Daily What]