I got my 4gb white nano shipped direct to me from Apple here in Japan, mostly because they weren't available in stores and I could get the custom engraving.
It arrived last week. When I unpacked it, I made the mistake of removing the face plate plastic and putting it over the metallic back of the nano. I thought it was the metal part which needed protection. I certainly would have bought a total body mask for the nano, like I have with my 20gb 3G iPod. However, nobody was (and is) carrying them here as yet.
Anyway, I decided I'd put the thing in my shirt pocket and use it on my 2 hour commute to work on the train. There was nothing else in that pocket, save the headphones which I kept on the back side of the nano to avoid scratches. Well, I was suprised to see when I arrived at work some smudge like marring of the screen in a couple of spots. There was nothing sticky or dirty in my pocket and nothing rubbing it (like a strap).
The next day, I looked at the nano and tried to clean it with a microfiber cloth. I hoped those smudges were just that, and would come off easily. Well, it had no effect what so ever. I tried a different microfiber cloth that I use to clean my PSP and found that it seemed to affect the smudges BUT actually scratched or streaked the nano screen! This is ridiculous.
I bought a small plastic/vinyl screen protector marketed for camera or phone LCDs and it covers up the smudges partially. Now I'm noticing the finish on the front of the nano still has such smudges - though I could live with those. And the metallic side is fine.
I'm very upset with the screen smudges, however. And I will go to the Apple store here to demand they replace next week when I have some time. This shouldn't happen to a $250 product kept in a loose shirt pocket for a couple hours. Given that they market this iPod for active and casual usage (in your change pocket!), Apple needs to come clean and fix this problem. I don't know if it is the finish or just poor curing of the polymer used. It's a DEFECT and should be dealt with quickly.