Here's a very cool E Ink display idea - PopSLATE is an upcoming project (trying to raise $150,000 at IndieGogo, currently they have almost $80,000) that aims to develop an iPhone 5 cover with an E Ink display:

In the beginning, they will only support Instagram (so you can show a photo on the E Ink display), but later on the will provide an API so more applications can use the screen. Pretty cool. They save they have "strong support: from E Ink, and hopefully they'll manage to raise enough money to start developing this.