OOOO
OOOO
OOOO
OOOO
. . . .
. . . .
. . . .
. . . .
Imagine each "O" is a photoresistor and each "." is an LED. They correspond logically on the arrays. There is also an LED in the middle of the photoresistor array that acts as a light source. In other words, this thing could detect black and white squares and use this as either a picture or a binary data source. The additional LEDs act as verification. Then at the touch of a button this data could somehow be stored or output to another robot. This could mean you use images instead of buttons for you controller... or you just made your very own very low-quality camera. Mull over that and tell me:
1. If it is possible, and
2. If it is, build it. I'd like to see it actually work.