EDIT: Can't reply to TeMPOraL, but I think that's not true, they need polarized light. I'm not an expert on this but my intuition is there are unrealized advances to be made in the field of reflective LCD-based displays. I just don't think there's much demand to research these applications and connect the dots. I would be surprised if you couldn't make a pretty decent, high refresh rate reflective display using an LCD based approach.
E-ink is nice because it does not need a light source to be fully legible in any condition in which print is.
There are already a lot of reflective LCD displays. For example in digital clocks and watches but they are all monochrome.
Pixel Qi promised reflective displays but I believe the reflective mode is only grayscale.
