Solar Heat For The Masses
One of my all time favorite products was designed by a Newfoundlander and is called the Cansolair. The Cansolair is an inexpensive solar panel made out of Plexiglas and recycled aluminum cans that can heat about 800 square feet of living space during the day. Here is a video from the CBC showing how the device works.
A solar heater of similar design could be made for $2-4 a square foot and significantly reduce the oil consumption of a mobile home.
Gordon