What are the three dots at the top of my iphone 3g?

Question

There are three dots directly to the left of the ear piece if you look really closely. There are two stacked on top of each other and one to the left of those. They are not on the screen, so what are they?

Answer 1

Those are the Ambient light sensors to turn the phone off while you have it placed to your face. You can reproduce it by covering them and watching the screen turn off.