Although its main focus is on communications and media playback, the iPhone offers a surprising amount of utility for cars. Developers have written numerous apps to help out drivers. Here are our favorite five free apps.
Pros: Uses iPhone GPS to determine proximity to speed traps, speed cameras, and red light cameras; audible warnings even when iPhone locks itself; users can easily report speed traps.
Cons:Red light and speed trap warnings can sound off too frequently.
The gist: Short of using a radar detector, Trapster identifies hazards to your driving record through an active community. This type of information used to travel by word-of-mouth, but Trapster makes it readily accessible.