I’ve been a longtime fan of E-ink displays, and while I prefer a full colour display on my phone, I love the idea behind the dual-screen ‘YotaPhone’.
The screen on the front is of the usual variety seen on most phones, and supports all the colours you’d expect, but the rear touchscreen uses E-Ink to display stuff, including images. It’s not small screen either – 4.7″, and consumes very little battery.
Here’s a promo video for the mobile. It’s available for pre-order in Russia and some other European countries.