http://www.physorg.com/news108666600.html

"The scientists want to find out whether the energy output from the burning hydrogen ... would be enough to power a car...."

Perhaps, but what use would that be? You still don"t have a power source. The more important question is where the radio waves come from. If you have to tote a huge battery around to power the radio wave generator, you"d be much better off using that electrical energy to directly power an electric motor, rather than losing more than 80% of that electrical energy through the hydrolysis and combustion cycle, not to mention the added cost of carrying a tank of salt water around with you.

Remember that we"re talking about a round trip from H20 to 2H2 + O2 back to H20. No surplus energy there. Only large net losses -- mostly thermal.