I have seen other ideas like this, but this one is definitively the most advanced.
While it proposes to beam a screen or buttons on your body, it does have sensors which are detecting the spot you are tapping on your body, such as you tap your palm or a finger, and the system knows where it is located.
That means that you basically program parts of your body to become hotspots, buttons to remote control devices, such mobile phones, mp3 players, games, etc. Of course, you can also display something on your body, like a screen, but the beauty is that working with sensors, doesn't make the beamer or a camera mandatory devices to detect your movements. Meaning that the device will become smaller and remain efficient in all conditions, even with a sunny day!
Stay tuned, this will come soon in your hands!