If you buy from an Apple Store, always always open your laptop and give the screen a looksie before leaving. Apple has free wireless, and all MBPs come pre-charged, so it's a simple five minute check to ensure you won't be coming back and playing the "i know it's not four pixels but please-please-please..." game.
I bought a Macbook for my wife a few months ago, checked it on a couch just outside the store: dead pixel. Took it in, got a new one, checked it, all set.
Just today walked in and picked up a new Santa Rosa MBP, checked it on the same couch, and what do you know: a big fat smeary thing (damage to the screen). Took it back in, got a new one, checked it, and good to go.
I bought a Macbook for my wife a few months ago, checked it on a couch just outside the store: dead pixel. Took it in, got a new one, checked it, all set.
Just today walked in and picked up a new Santa Rosa MBP, checked it on the same couch, and what do you know: a big fat smeary thing (damage to the screen). Took it back in, got a new one, checked it, and good to go.