This app from iOnRoad turns your Smartphone into a Personal Driving Assistant. This app (Android now, iOS to come) mounts in the center of your windshield and uses the built in video camera to look at the road ahead. It then computes the closing speed to vehicles or objects ahead and sounds a warning if things are moving too fast.
What does this mean ? It means that there are another pair of ‘eyes” on the road immediately in front of you. Collision warning, lane departure warning, and when you leave the car, a handy feature that allows you to locate your car when you come back after a flight.