University of California Berkely has some technology available.
TTD@lbl.gov Http://www.lbl.gov/Tech-Transfer.

 Electochromic optical switching device
 Made of electrically conductive films, electrochromic film and a
reversibly polymeric electrolyte to make an opticle switching device for a
variety of applications.
 The device consists of five layers. The electrochromic film is switched
from transparency to opacity by controlled ion movement caused by minor
changes in electrical current. Applications include energy-saving windows,
eyeglasses, watches and computer display screens. Maybe even automobile
glass that tints when you press a button. PIC apps?

Automobile Fuel Atomizer.
http://www.bluecrow.com/fuel2000