This is a very old question, and there are some good answers. I just wanted to add another excellent example from the movie White Nights (1985), starring Gregory Hines and Mikhail Baryshnikov. In the scene where Gregory tap dances in a studio, the camera pans with him as he runs in front of a wall of mirrors. You can see it at 2:11 in the YouTube video below.
I had to watch the movie twice in a theater to figure out how they did that! If you look closely, you'll notice that Gregory's reflection disappears briefly. That's because the two mirrors that should be reflecting the camera are actually angled slightly away. Specifically, the mirror to the right of the camera is angled to the right, and the mirror to the left of the camera is angled to the left. Neither of them reflect the camera. You can see this when Gregory runs past; his reflection disappears for a few frames.
The third picture above doesn't show his reflection (and not just because he's blocking it).