I just read an article at Inhabitat about an Israeli firm that’s working on a road surface with embedded piezo crystals capable of generating electricity as cars pass over it. From the article:
The energy-generating roadway works thanks to piezoelectric crystals embeded in the asphalt. As vehicles pass over them, the vibrations generate a small amount of electricity that travels to a larger transformer which then distributes the energy. The generators can be as thin as a few centimeters or can cover large expansive surfaces, and can be easily adapted for a variety of different transit systems including roadways, railways and even airplane runways.
Okay, that’s awesome. Read more about it here.