Well now THAT'S a pretty nifty idea. Besides the fact that it just looks cool, having an e-ink screen on the back of your phone makes quite a bit of sense. The screen on the back is the same kind of screen you would find on a kindle reader. So anytime you need to peek at any of your notifications or email, you can use your second, less power-hungry, anti-glare screen. Hopefully they'll link up their screen with the iBook app in the future.
Check it: inkCase i6