Trapster - Five mobile social networking services

Stay out of the crosshairs of the police radar gun thanks to Trapster, a free mobile social alert service that enables motorists to share real-time information on highway speed traps. The device-agnostic application is like a next-generation Fuzzbuster: Users who spot a state trooper or traffic cop lying in wait simply punch a button on their handset, immediately alerting all other drivers in the vicinity to slow down and proceed with caution. Over time, Trapster determines the credibility of traps based on user agreement, and establishes each user's credibility as well. You'd think the cops would hate it, but an endorsement on the Trapster website credited to Bill Johnson, executive director of the National Association of Police Organizations, reads "If someone slows down because of it, it's accomplishing the same goal of trying to get people to obey the speed limit."

See a video of this application here.

See it at http://www.trapster.com/