It looks like Motorola is the first to put “back-of-device interaction” into production. That’s an idea that HCI researchers including Patrick Baudisch have demonstrated in the past few years (see his nano touch page for details). Putting a touchpad on the back of a device gets your fingers out of the way of the screen and gives potential for more precise interaction as well as new types of gestures.
via Touch Usability
More at Slashgear and Engadget. (Images from Slashgear.)I’m happy to finally see someone put this into production. I don’t love the industrial design on this particular device but as a feature I think it would make for a really pleasant browsing experience once you get used to it.