TrackIR is basically a new form of input that “tells your game exactly where your head is, in 3D space.” Video demonstration after the jump.

You can make your left/right rotation very fast, so you can turn 180 degrees in your game by just moving an inch in real life. You can then make your up/down rotation very slow, perhaps because you’re in a car and there’s nothing of interest to look up or down at

Video 1 – Introduction

Video 2 – GTLegends Demonstration