Dumb question I'm sure, for which I apologize in advance. I bought my first mac, a white mb, about 18 months ago. Rather stupidly, I still don't know what the key next to the right hand command key does. Anybody? Alternatively, for those with a wired Apple keyboard, it's the key at the very bottom right hand corner of the keyboard. All it appears to do is make the pointer vanish. Is that it? Surely not, as that'd hardly warrant space on a laptop k/b...would it?