QUOTE (OvertheHill @ Sep 26 2009, 01:45 PM)

Must admit the gps drains the iPhone very rapidly indeed. Like the look of these devices. Do you get many false alerts? By that I mean if you are travelling down one road near to another that has a camera?
Yes, you do get false alerts. The device uses a common data base (the one from Pocket GPS World I believe) so if that has errors the device reflects them, but there is provision to suggest amendments if you can see that things are wrong.
The other factor that affects the false alerts I believe, is the proximity setting that you use. You can vary the time interval between getting the alert and passing the camera. If you make the interval short you reduce the proximity area and have less chance of picking up cameras on adjacent road but you also have less time to reduce your speed if necessary.
If you make the interval long, you increase the proximity area, giving yourself more time to take action, but also increasing the chance that you will detect cameras on adjacent roads.
For example, if you set a 30 second delay and you are doing 80 m.p.h., you will cover 1,173 yards in that 30 seconds so the device needs to detect a camera (say) 1200 yards away. Near junctions, there may easily be another road with a camera within that sort of distance.