In fact if you have two projectors and two screens you can have double the fun for under $30.
Additionally, If you only have a standard projector that displays a 4:3 image vs a 16:9 image, you can just go to target and pick up one of the home essential frost shower curtains. They are 72" x 72" and hold light better than the EVA Shower Curtains.
Note: The Picture I have attached is shot from behind the curtains where the projectors are located. Rear Projection means that the majority of the light, colors, and image vibrancy are seen from the other side of where is picture was taken. So just trust me on this one. $14 is a steal for one of the largest rear projection screens you can buy for under $600.
Hope it helps leave questions and / or comments below.
Well there you have it !
Bob's your uncle.