This is a little odd, but a nice find I think.

I recently found at a local GoodWill a 40" x 40" Tower brand projection screen.
It seems to be in really great shape.

Made compleatly out of metal, with a tripod base and telescopic supports that bring the screen out. Pretty typical I suppose.

One thing I thought was kinda unique was that the screen its self is a silver color and quite reflective.
Even with my mostly dead projector shining on it, colors really come to life with a clear, bright picture. Definitely a huge improvement over my yellow walls.

http://i31.tinypic.com/214y4nn.jpg

I fold it down when I'm not using it
http://i31.tinypic.com/24lueeg.jpg

There is just one little tiny tear in it, no idea how to go about fixing that..
http://i32.tinypic.com/35mfvw3.jpg

The projector I'm using is a really old Sharp Notevision. It would normally put out 500 lumins but due to age its probably closer to 400. The picture always looked pretty crummy against my wall. I think this screen really makes a big difference.
Lights on: http://i27.tinypic.com/2yjpi1l.jpg
Lights off: http://i30.tinypic.com/2vxo97c.jpg
(Opening scense to Okami (http://en.wikipedia.org/wiki/%C5%8Ckami)).

This is the type of screen I use for real film slides. The brightness is good, but it limits the resolution somewhat - noticeable compared to the high resolution in a Kodachrome slide, probably not noticeable compared to the normal resolution of your Notevision.

I have not tried to repair a ripped one, but I'm guessing that it's fabric and if you pull it out face down over an ironing board and apply a patch to the back, it might work.

One of the few remnants from my bachelor days that Kim lets me keep in the living room is a projection screen that I mounted to the bottom of a high shelf. A pretty decent sized one, I use it for the (very) occasional times when I pull out the 16mm or other old projectors. It never really occured to me to use it with a video projector...if I should ever have one land in my lap, I just might talk Kim into that.