My latest article for TheFeatures is about haptic interfaces, which send information to your skin.
At Nokia Research, Jukka Linjama and Topi Kaaresoja added a small acceleration sensor to a phone to create a Pong-like game that a user controls by tapping the phone either horizontally or vertically. The user gets feedback from different vibration patterns. In a paper presented at the NordiCHI human-computer interaction conference, they wrote that the synchronized combination of graphics and vibrations "creates a kind of a kinesthetic illusion of a soft ball being tapped and bouncing inside the device. In informal evaluations most users rated this illusion very natural, impressive, and enjoyable."Link