Weaponised flying armour – Iron Man (2008)
The paradox in robot power is that the on-board energy needed to fly makes the system heavier, which adds to the energy required for flight, so getting it off the ground will be the trickiest challenge.
But whatever company solves it stands to make squillions in military contracts.
Ultralight materials will make flight more likely than iron, but make it more vulnerable to villain attack.
Time machine – various
While literal transport to another point in history remains scientifically impossible, it is theorised that orbiting the Earth at near light speed for an hour will result in everyone else being decades older when you come back – a theme that was explored in Christopher Nolan’s Interstellar (2014).
Might there be an industry for space-borne tourists who want to live to see the future?
Time, gravity and speed affecting each other is a principle of physics already, but as for the HG Wells book The Time Machine and the Delorian in Back To The Future (1985), Einstein (the physicist, not the dog in the film) says “never”.
2150, when we can build something fast enough.
Hoverboard – Back to the Future Part II (1990)
Just in time for the 2015 deadline, the Hendo hoverboard exists, poised to capture a new generation of shredders. Even astronaut Buzz Aldrin and former pro-skateboarder Tony Hawk have used one.