For years, truckers and other drivers wishing to dodge speed traps and roving bears have used the CB radio to exchange on-the-road updates. Now, using the potential of the iPhone, two startups offer a 21st century solution to the same problem.

Trapster members report speed traps as they drive by double-tapping the map display on their iPhone, then dragging a marker to the appropriate location. Nonmembers can also report in via an anonymous tipline. The user can also append notes to the report. Using the phone's built-in GPS system, Trapster then feeds alerts to members as they enter active speed-trap areas. Trapster also works on Garmin, Tom Tom, and other navigation devices. The service is free.

Njection Mobile uses a base of Microsoft Virtual Earth on which to plot user reports of active speed traps, which is also fed back to users as both map data and in speech form. The NMobile download will run you $4.99.

Both offer internet-based traffic maps containing tags for red light cameras and typical police surveillance locations, as well as currently active setups.

Of course, as any CB user knows, real time speed trap data depends on lots of data points, and such systems are of little use if there aren't a large number of people inputting data regularly. This tech is still in its infancy, and it's anybody's guess as to which network will gather a critical mass. The idea is tried and proven, though; just ask any trucker.