At the User Interface Software and Technology Conference Microsoft Research is showing off a technology they call “SideSight.” Basically, it’s an IR proximity detector placed on the sides of small devices so that you can track finger gestures. This is kind of like the inverse of IR positioning systems that face toward the display direction to track touch points.
In a bid to outdo small device multi-touch, I think the SideSight team is missing the bigger picture here. What they are basically doing is using a linear array camera on the sides of the device. In other words, a true “side sight” technology could provide features that go beyond finger gesture recognition.
Gesturing is one form of user input and whether it’s a good idea to try to limit the gesturing like this or come up with a more generic solution, time will tell.