Where's the backlight? (Score 2)

I'm sure they are working on something for this, but most LCDs do not primarily work by reflection, they work by filtering out the parts of white light that you don't want in the image. So, how do you backlight cloth? or a little rollup screen?

Has anyone has seen the iPaq without the backlight on (which is by far the best non-backlit LCD I've seen)? It is still unusable in non-office lighting conditions. And that is a best case scenario.