Does the iPod Nano 4th Gen actually scratch? I've been eyeing this iPod Nano 4th Gen case. I'm just not sure if I really need it though. I've owned a 3rd generation regular iPod before and I didn't put a case on it and the back side was scratched pretty bad but this new iPod Nano seems pretty durable. Ppl who have owned the iPod Nano for a while now, lemme know how your guys' iPods turned out?