I kinda impulse bought a Ninebot (company that bought Segway) Mini Pro 320 for ~$300. Quite a bit more than the $100 hoverboards I have been tempted to try, but I understand these to be more refined, and I want my dad to start using one instead of driving a car the 150 yards to my grandparents house. I'm also considering it for my wife who walks to work about half a mile away. It basically only seems useful for replacing walking/jogging places with a top speed of 10 MPH and range of 12 miles.
Then there is the Inmotion V10, with a top speed of 25 MPH that looks like it could more than replace bicycle commutes. It seems the superior way to commute in Manhattan, for instance. At $1000, it will be a long time before I get one, but my interest is piqued for sure.