Whistler's RCL-250 light and speed camera detector uses GPS to warn the driver of upcoming speed traps.
The device comes pre-loaded with a database of 6,000 known red light and speed camera locations. Database updates are issued monthly, and can be installed by connecting the detector to a PC (sorry, looks like no MacOS support).
Fletch- I believe the model number is the Whistler's RLC-250 (not RCL).