If the Back To The Future trilogy is to be taken as historically accurate, which of course only a truly insane person would do, we are at most 20 months away from the invention of the hoverboard.
Exciting stuff, but small fish compared to Doc Brown's eventual invention of a flying, time-travelling train that "runs on steam", as seen in Back To The Future Part III.
Whichever of the two you'd prefer to get your mitts on, you're in for a bit of a wait. So why not browse our 20 things you (probably) didn't know about the third instalment to kill all of, oooh, 10 minutes...
(Images: YouTube, Rex, Wikipedia)