Among the rush of Apple patents relating to touchscreens over the last year came one on tactile feedback touchscreens, and Nokia seems to have been thinking along the same lines. Almost exactly the same lines, since Nokia's Haptikos tech is a system of fluid-cells driven by piezoelectric actuators that push up through a flexible touchscreen. And that sounds a lot like Apple's sub-surface, adjustable tactile "keys." But apparently the Nokia tech is aimed at "variable and controllable user perceived surface roughness or friction coefficient" rather than buttons. Fascinating stuff, nevertheless. [Unwiredview]