Computer Controlled Cat Door
 

This is Flo. Her job is testing our image recognition algorithms, although she might not be aware of this. She goes in and out of the house through a cat door.She also has a habit of catching various animals, dragging them inside through the cat door, and letting them loose so they can be chased for hours. Very cruel. To put an end to this we have built a computer-controlled device that visually determines if Flo is carrying anything in her mouth when she enters, and if she does, it simply does not let her in.

http://www.quantumpicture.com/Flo_Co...lo_control.htm

My cat would be scared ****less from the clicking. I would need a silent revision for my cat :) ^^
Great idea though :)