Sony Ericsson has filed a patent application for projector technology inside mobile phones. According to the application, when the projector beams the desired image on to a surface, the onboard camera will take an image of the projected image to analyze if any adjustments are to be made. Thus you can change the intensity of the projector to get the perfect image. The developments are currently under the process and there are several mobile phone samples with the inbuilt projector. Probably this technology will sometime be as customary as built-in cameras today.