I have a 5 yr old powerbook g4. The part where i rest my wrist on is pitting, looks like its chipping in a way, these areas are like little black spots. Do you guys know if the new aluminum on the unibody mbp are made the same way? I hope not. I like to clean down the aluminum body on my mbp, but wonder whats the best way to clean it? I don't want to take risk in damaging it down the line by using anything harsh. I hope the sweat from our skin won't eventually cause PITTING like the old aluminum powerbooks/mbp. That's all I am worried about.