I have a new uMBP 15" and i take it with me pretty much everywhere. With an old Black MB (& MBP i think) i saw feint rub marks on the screen when looking at an angle - where some of the keyboard had rubbed against the screen. It was probably the bag i had at that time which meant MB knocked against my hip from time to time (I have a much better bag now - Crumpler Cheesy Disco - so its on my back and the screen side is always facing out.) But does anyone put a protector between the screen & keyboard when they carry it around? Should i use the microfibre cloth you get with the MBP? Will this increase or decrease the chances of rub? Do i need to do this? Does anyone do anything along these lines?