This is like the head tracking with the wiimote but all that is needed is a pc and a webcam, even my very low quality webcam works!
Step 1: Connect a Webcam...
Connect your webcam. the software requires that the webcam is connected and working before it is opened.
Make sure the webcam is above the screen roughly in the middle across the top.
Doesnt matter how good the cam is really although im assuming a better camera might work better than mine.
Step 2: Download the Software...
go to http://www.kuubee.com/index.php/2008/02/28/virtual-viewpoint-code-download
to download the software that i used. (I have nothing to do with making it by the way.)
Download the file extract and run the virtualviewpoint.exe.
If its all working well it should start to a black screen, turn grey and then look broken.
Hit the "S" key to start tracking your eyes.
Step 3: Enjoy the Vr Headtracking!
When using it press space to align your eyes when your looking at the centre of the screen.
Press "S" if it looses your eyes completely.
In config.dat you can change aspect ratio and a few other settings.
By making your own bubble.png and background.png files you can change the images in the program.
First instructable hope you enjoy!