Hi Henry
I fitted a screen protector on my Canon 40D that consists of a thin frame that surrounds the LCD and an opaque, flip-up cover. The flip up cover also helps shade the LCD in bright sunlight so you can easily check the histogram and see some detail in the replayed image too. I would definitely recommend them for the shading alone.
Mine looks like this model.
http://www.delkin.com/products/popupshades/mini/
Cheers
Dennis