Interesting topic guys. Unfortunately things aren't quite as simple as that article makes it seem. I will guarantee that the energy used by his radio wave device is more than the energy available in the hydrogen produced. By the laws of thermodynamics it has to be, and they've held up pretty good for the last couple hundred years.
That would be called an "overunity" reaction. A type of perpetual motion. People sure have been looking, but no ones found one yet. Hydrogen is not an energy source, its an energy carrier. The energy used in splitting it from water is always more than what you get back. Even a unity reaction (1:1) is impossible. There is always a loss (entropy). This is true of any physical reaction.
What you need to look at is getting free, clean energy to obtain the hydrogen(solar, wind, etc.) Google solar electrolysis, it can be done pretty cheaply on a small scale. I think the Dutch actually have some solar powered hydrogen refueling stations for the public.
And if we're talking about automotive uses, since you've gone through all that trouble to get your hydrogen, you'll want to use it as efficiently as possible. The rotary is sure alot better than a piston engine but still internal combustion is not the way to go. Fuel cells use the reverse of the electrolysis reaction to produce electricity. There are electric motors that can approach 90% efficiency. You also get the benefit of dynamic braking where the kinetic energy of the moving car is reclaimed instead of just being wasted as heat (the current brake pad system).
I didn't put this here to shoot anyone down or anything. I think about this kind of stuff all the time too when I'm buying $4/gal gas! The best things happen when everyone is throwing out ideas.