Genuine V.R. with smell, touch, taste etc. for games, socialising and learning.
A cheap and efficient space drive.
Broadcast power from space.
1920’s Style Death Ray ?
Direct stimulation of the brain’s pleasure center would have very far reaching applications. Remember if we can cause pleasure we can also cause pain. Horrible, extreme, intense pain that can be kept of for a long time since it cause no physical injury and leaves to no marks. It’s the perfect method of torture. Nobody said the “Next Big Thing” had to be good.
They already have. It’s called a “hand.”
With apologies to begbert2.
That would be important, but what reason have we to think it’s possible? What we need is a constant-boost drive, one that can constantly acclerate/decelerate instead of just drifting towards the destination; that’s the only way to get even as far as Mars in less than a year. But at the present state of technology, a spaceship has to carry its reaction-mass with it, with means a lot of practical limits; one big push at launch is generally all you can afford. Maybe a Bussard ramjet – but we’re nowhere near perfecting controlled nuclear fusion – or an Orion craft – but would you ride in something propelled by nuclear-fission bombs?! And it wouldn’t be cheap.