People have made head tracking systems by mounting the sensor bar from a Wii on the brim of a baseball cap, and then placing the Wiimote on the top of their scr

People have made head tracking systems by mounting the sensor bar from a Wii on the brim of a baseball cap, and then placing the Wiimote on the top of their screen. I saw a video of someone playing Half Life 2 with it, and it looked to be surprisingly effective. Also, the difference between the Oculus Rift DK1 (which does not have positional head tracking) and the DK2 (which does have it) is pretty incredible. Obviously, the type of virtual environment you're dealing with has a huge effect on how strong the illusion is.