Nothing burns fuel (or patience) faster than stop and go traffic, something MIT researchers are hoping to minimize with SignalGuru. The smartphone-based system commands you to slow down or speed up based on whether the light is green, yellow or red to help avoid gas-guzzling activities like idling and accelerating -- reducing fuel consumption by 20 percent. Unlike Audi's Travolution system that relies on WiFi and 3G to communicate with traffic lights, this latest development uses your smartphone's camera to detect signal status and create a Green Light Optimal Speed Advisory (GLOSA), which will predict and learn traffic light patterns. So far it's only been tested on the iPhone in Massachusetts and Singapore, but researchers hope to expand and commercialize the system, eventually including voice prompts and features like GPS navigation with add-ons such as parking space availability and local gas prices. Anti-road rage technology not included.