I worked on the electronics for a home fueling station a few years ago for this company called Fuelmaker.
Not sure why this has not taken off yet other than the cost of the unit
http://www.fuelmaker.com/Products/NaturalG...Residential.htm
home version
http://www.myphill.com/
What pisses me off is that it is a Canadian company, yet they do not sell it here.
Probably some government beaurocracy crap!