I've had this computer, and therefore this mouse, for well over a month. And just now, I found out by accident that the protruding bit that looks a bit like a...ahem...nestled between the left and right clicker is NOT a design feature. It's a little wheel that if you touch it when the cursor's on the scrollbar, helps you scroll up and down more easily!
Hee. I wish someone had told me that before.