Cars that run on water

I've heard this story fifteen times in my life. Every couple of years there is some guy who comes along and swears he has invented a car that runs on water. Either, they are all full of crap, or there really is something to this and the people who invent such things get disappeared in one fashion or another. I hope this is the real thing. I hope we all find ourselves running on water in five years. I hope water prices do not go through the roof.