Youtube demo here:

 http://www.youtube.com/watch?v=YbwSl5Hp3r8

This is a round about way of using a servo to move an analog sensor to 3 points to triangulate the servo degree where the photocell experiences the most light.

The servo sweeps back and forth and then another servo points to where the brightest point was.

It is very simple wiring, but the code is a little fancy. It’s all commented up here, but as always deduction is your friend.

Raspberry pi soon?