How Much is Your Roof Worth?

Al Gore's Solar Roof

"RoofRay is a fantastic new Google Maps hack that allows you to zoom in on any American address' rooftop, specify the surface area available on that roof for solar panels and then calculate the potential power of the system, in total and per square foot. You need to know some arcane details — like the roof angle, a good guess will do— but it's an excellent resource if you're trying to get a rough independent gauge on whether an investment in solar power would pay for itself any time in your lifetime." Boing Boing