Here's a tiny demo of using the opencv face finder on a PIL image and displaying the result with pygame:
That's using the SWIG opencv interface (available on ubuntu from the python-opencv package), not the recently-released pycv (which I know nothing about).
My headtrack project is an attempt at something like Johnny Chung Lee's head tracking project. I tried opencv since I don't have a wiimote yet. My goal is to move my desktop windows according to my head position, so I can peek around a window or lean in to look at windows that are outside the normally-visible screen.
Meanwhile, the compiz hackers started a similar project.
