Another Fox News report
http://www.freeenergynews.com/Directory/BrownsGas/WaterFuel.wmv
Having viewed that I still find it suspect.
The bottom line is that energy is a constant. Whenever a material changes state energy is released in the form of heat, light, or radiation.
So the process of changing state from H20 to HHO which I think is either mischaraterized or just plain absurd would require energy from the alternator which is getting it's energy from the engine, which is not 100 percent efficient either.
Sorry, it just doesn't wash with me.