I put the nano in my pocket with a bunch of keys and coins and went about my business around the house for several hours. The nano's aluminum body showed some very light scratches after this, but none on the screen. I then put the nano into my laptop bag with more keys, coins, my cell phone, a digital camera, and a number of other random knick-knacks. I continued to go about my business, but made special effort to rustle around my bag more than usual. After several hours of riding in my backpack, the nano came out with a few more minimal scratches, but still significantly less than the first generation, plastic-cased nano would have under the same treatment. Best of all, there were still no noticable scratches on the screen. Perhaps Apple changed the plastic on the screen to something more durable?