Here is a reality touchscreen that is 10 metres long! Take a look at the video below, it looks real good.

Behind the long screen are six cameras and 16 infrared lights. When you touch the screen, a small amount of infrared light is reflected back and the cameras sense the position and then translate that into coordinates on the surface. It is curved over 135 degrees, thereby creating an immersive environment.

http://www.crunchgear.com/2011/02/08/reality-touchscreen-is-10-meters-long-accepts-100-touch-inputs/