Virtuix has updated his Omni and presented it at CES 2014. The Omni is a virtual reality interface that consists in tracking leg movements as we walk on a static rig (as shoes are designed to slide to the sides of the rig). A video will demonstrate this better than I could describe it!
This may of course be combined with Goggles like the Oculus for great immersion in virtual reality. But unlike Oculus (that I commented to be too much focused on the gaming industry which seemed to me quite limiting), this video clearly shows that, on top of gaming, virtual reality can also let the user go through towns, apartments and jog in wonderland!
Specially for FPS games, this controller may also be combined with a gun controller as we see on the following photo: