Tim Bruysten forgot his »Apple Mighty Mouse« after his presentation on Web Monday meet-up. I took it with me to hand it back to him later. I am using it now. And I have to say: I don’t like it.
I don’t want to go into too much detail, but generally the absence of physical feedback for the three different “buttons” requires the user to get that from the visual/acoustic feedback on screen. The presence of two more buttons is not visible and not haptic. So it remains a mental concept.
It is a nice object to explicate the notion of affordance.