OK, the correct term is "Backyard Theater" but you get the idea.  
Is any one else doing this?   As part of a separate project I now have some fun AV equipment.  So I'm setting up a backyard theater to show movies for my kids and the neighbourhood.  
So far I have the 
projectors, wii's, 
sound system, dvd players and I just found the screen I've been looking for:  
A 24' x 12' white tarp for $30 bucks.  The size is almost a perfect widescreen format (~ 21x12)  I'll make a "frame" using black duct tape on the tarp.  
I think this calls for "Curse of the Black Pearl" as a debut feature.....