I am definitely playing with eye tracker!
I've always wanted to have a piece of technology that adds a bit of immersion for the viewer so they can see exactly what I'm looking at.
It also helps optimize my gaming experience as I can tell through hot spots after I finish playing a game where my most viewed sections of the screen are and for what game.
The last bit is that I intend to start playing games that utilize the Tobii Eye Tracker 5 to help like in Star Citizen or DSC both of which I do own and would eventually love to dive head first into but am still getting use to the Tobii Eye Tracker 5.
Star Citizen is hard enough without eyetracking :D i tried it once with my hd webcam but i wont use it :D