Cost: FREE
Compatibility: iPhone, Android

What makes Waze super cool (besides it being free) is that, along with full GPS capabilities, Waze users can contribute to live updates on everything from traffic jams to where the cops are stationed. Waze founders call their burgeoning network "a personal heads up from a few million of your friends on the road." We say power-down the Garmin and download yourself a fresh version of this killer app.