There aren't very many hydrogen cars on the road these days, but there might be soon. And when there are, it will be possible to take the dirty water from your toilet and turn it into fuel.

Car sharing isn't new, but what if it was your car that was being shared? A new crop of peer-to-peer hourly car rental companies are popping up--can they gain traction?

Where Matternet is going, it doesn't need roads. But the people there need food and medicine. And these drones can bring it to them.