I know this is only tangentially related and i'm not sure any of you will be interested but CIG, the company behind Star Citizen, is developing some pretty interesting face and eye tracking that works with really low resolution cameras. No setup of any sort just turn the setting on and not only does it track your mouth for speech and shit but it's tracking your whole face well enough to pull funny faces and shit, shapes that you wouldn't really expect it to deal with. 

Of course, being star citizen it is glitchy and broken as fuck and either works well or doesn't work at all. But it's interesting technology.
If those dumpasses can get that working on shit webcams, what can people who know what they're doing with custom hardware achieve I wonder?