Take a peek at this iPhone app by Casio called PicapiCamera, which works as 21st century version of a signal lamp. Users of the app can receive data in a specific pattern of flashing red, green, or blue (RGB) lights found on digital signage or other PicapiCamera users' devices simply by pointing their iPhone in the right direction.
Currently, you can download PicapiCamera free from the Apple App Store. The app enables you to take a photo and send it other users of the app through the aforementioned visible light communication technology.
The flashing RGB pattern contains a tiny piece of 8-bit data, and when the receiving phone sees that, it "reads location information and retrieves the applicable data from the cloud server and displays it in the photo shot by the camera," according to Diginfo.tv.