Well the reason I ask is because I used to have a projector for my flight sim. I noticed that the projector, and probably most projectors, are designed to display on a flat surface. I noticed if I walked up to the screen and curved it by pulling on the edge a little, then the image would be out of focus at that edge.
I remember that some guy was working on a project where he was going to reflect the projector image off a curved mirror so it would display on a curved screen, but I'm not sure if he ever finished. If I find that website, I'll post the link.