Cost: FREE
Compatibility: iPhone, Android, Blackberry, Windows Phone

Social networking isn't just for stalking old girlfriends and updating friends on the progress of your cat's urinary tract infection. No, some people are actually using 'the network' to save tons of cash. Trapster is a relatively new app that is dedicated to sharing the locations of millions of speed traps and road hazards around the country. The genius of the whole setup is that users are the primary source for up-to-the-minute information. So go ahead, put the pedal to the metal ... as long as you have Trapster.