Install a HHO rig on '79 Honda Accord

I'm wondering if anyone knows about a HHO rig
and if it's real?
I saw this site at h2own.com
they explain:
One can run their car on water
with such technology and
claiming the technology they're offering can
increase horsepower of the car, cleans the emission,
scrub old carbon and sludge and increase the cars mpg
by double or more...
Have anyone heard of this?
Is it real?
If it's real, do you think I can install it on my
'79 Honda Accord with CVCC engine?