HowStuffWorks writes about the top 5 i-Phone applications for your car.
We especially like Trapster. Trapster permits you to scan your area for known speed traps, police hang outs, speed cameras or even stop-light cameras. It can give voice alerts of approaching speed traps and compensates for a driver's speed and direction in radar to relay accurate warnings. Signal cameras and police traps also show up on the display as icons. Registered users can also receive text messages for real time police reporting.