Business idea: create an Internet data base that ties in with global positioning systems.
When a driver sees a red light camera, he/she presses a button on a device that sends the GPS location to a centralized data base. Then, whenever a driver who subscribes to the service approaches that location, their GPS device warns them that a red light camera is present.
To avoid abuse, e.g. by municipal officials who see this as a revenue source, registration and possibly a fee should be required to send camera locations to the system. This would prevent municipalities from flagging every location in sight (including the middle of Interstate highways) to interfere with its effective use. Also, perhaps require the same location to be flagged by a given number of separate users.
No one can complain that this would work against traffic safety because the warning would make people more likely to stop when the light turns red.
Many in-vehicle electronic devices (radar detectors and GPS) already have this feature. I know Escort make a detector that costs about $400 (I know, expensive at first, but in many areas cheaper than a ticket) that you can connect to the network via your computer and download the known red-light or speeding camera locations. Some of them even track speed traps.
I think there is an iPhone application for that already.