Trapster® iPhone App
It has full support for the GPS features of the iPhone 3G. See the detailed help file in the application for full instructions. (Click the "i" in the lower right corner).
Here are some images from the application:
Main Screen
The red dot shows your current GPS location. It follows you in real time. The size of the red dot shows the location accuracy the iPhone 3G is able to obtain (a very small red circle means the iPhone 3G is able to pinpoint your location with great accuracy). The emanating red lines show the alert zone. The alert zone is directional, and dynamically narrows and elongates as your speed increases. Icons animate while the corresponding audio alert is played.
Trap Detail Screen
This screen shows more information about when the trap was reported, the confidence level, and who reported it. It also allows you to rate traps that were reported by other users based on whether you agree or disagree.
We highly recommend that you get a hands-free kit with car charger and dash mount like the one pictured below. Click the image to check pricing from Amazon, or get one at your mobile phone retail store.

Trapster® is still in a beta testing phase. This means you may experience bugs or deficiencies in the software from time to time. Issues? Please feel free to contact us.