Research 5 “above the neck” tracking by others.

http://www.youtube.com/watch?v=5sPh6-J9wOA
The Seeing Machines’ faceAPI, sophisticated face tracking program.
http://www.youtube.com/watch?v=AA_ebIOkYN4
One application of the usage.

http://www.popsci.com/technology/article/2011-09/creepiest-video-software-ever-substitutes-faces-real-time
Face tracking with realtime mapping by Kyle MacDonald and Arturo Castro.

http://www.instructables.com/id/Face-detection-and-tracking-with-Arduino-and-OpenC/
Face tracking with moving camera.

http://vimeo.com/34442645
Face tracking for makeup artist.

http://www.youtube.com/watch?v=WIoGdhkfNVE&feature
Face and gaze tracking.

and one more….

http://www.youtube.com/watch?v=ku3xbh22GBI&feature
Face expressions mapped to 3D animation.