I agree with Stryker. I have a nano that i dropped yesterday and the screen is pretty scratched up. But then you have to think about the nano. It's tiny. Unless they made it out of strengthened titanium or something like that there's no way that its not going get scratched, break, etc. I think Apple should have a case for the nano, which helps a lot. My friend has a rubber see through case for his and it doesn't get scratched. WHen it comes to the screen itself breaking, thats pretty rare actually. The only way to break that screen is to run over it with a car! I mean, u can stick it in your pocket or your backpack and it won't crack. here's a review on it:
http://arstechnica.com/reviews/hardware/nano.ars/3