Hydrogen Assist Cells? Anyone tried one

[outsidr]

Has anyone tried a hydrogen (HHO) assist cell to try to increase their mileage. I am researching the concept but have little real world user's who have good results or well documented experience. I would be great full for anyones experience with these thing. I mean, the space shuttle is launched by the stuff so I'm thinking it might work...Thoughts..

Thanks in advance... Please no lectures on the conservation of energy, I get that part...