FOR SCREENSAVER:
* use [Un]Inhibit together as a SimulateUserActivity workalike
	* disablegss.py from http://ubuntuforums.org/showthread.php?t=284804
	* this method doesn't work either.  tried in gss-poke.py
* xdg-screensaver suspend / resume to SimulateUserActivity
	* http://tronche.com/gui/x/xlib-tutorial/2nd-program-anatomy.html
	* http://portland.freedesktop.org/xdg-utils-1.0beta3/xdg-screensaver.html
* SimulateUserActivity
	* does it work on other people's machines?
		* find if other people have their gnome-screensaver run even if they set
		screensaver timeout to 1 minute and run:
		for ((i = 0; i < 999; i++)); do
			sleep 50;
			gnome-screensaver-command --poke;
		done;
	* find irc channel to ask if my understanding is correct
	* file bug
	* track down bug
		* compile gnome-screensaver
* cli opt parse
	* quiet mode
		* no display window
		* no text printed to terminal
* fire up the face detector only just before going to inactive mode.
	* that way the camera isn't running all the time
	* maybe start 10 seconds before going inactive, then run until activity
* be more aggressive with turning off the screen.  dim the screen as soon as
it's not being looked at.  turn it off soon thereafter.
	* could be enough to save battery.  would need to power the camera sometimes,
	but would save on backlight.  need to test.
* don't prevent sleep when face is detected, but user isn't actually looking at
screen.
	* requires pose estimation.
	* also requires estimating the direction of the eye.

OTHER IDEAS:
* authenticating a user based on face recognition (as opposed to face
detection)
	* much more difficult to do reliably
	* use object tracking and emotion estimation to require a set of facial
	expressions as authentication.
		* awesome for people who find typing hard, eg: no hands