I went to an SGI demonstration a few years ago when they projected on to a curved WALL - and sat you within the curvature.... (ie if viewed from above, and the curve of the screen is the curve on the letter D, the seat would be half way down the vertical, and inwards a little) the idea being that even the extremeties of your eyes were seeing the picture on the wall. They then played some demo where the camera viewpoint flew over mountains, and as it plunged into ravines, I almost fell off the chair, and my stomach practically fell out of my bottom.

The screen is a nice idea - but I WANT THE WALL!!!