I did consider that - and it's not off the drawing board.

I was concerned with the amount of bending anything reflective attached to the back of the screen might suffer - I was also worried about possible damage of the front facing screen (it's a glass beaded screen).

I suppose if it came down to it, I could drill a small hole in the support behind the screen (it's held free-standing from the wall/ceiling by two large timber towers - full of dvd's ) and stick something reflective to the backside of the felt side strips.

I've looked at http://www.rentron.com/PicBasic/infr..._detection.htm for the basic idea - I just need to find something that's reflective, sticky, and can handle being rolled and unrolled over and over again.