Re: scratched screen repair
There is a paste/wax kit for scratched ipod screens that will work. It's pretty much a straight forward "buff-out". Labor intensive, but worth it. Found it in BestBuy, if I remember correctly.
Some people have tried brasso, applesauce and toothpaste as a buff agent. I would be worried about the brasso and the plastic parts of my phone. Applesauce would appear to be a bit runny, I wouldn't try it myself. I've used toothpaste on my glasses, but I've never had a deep scratch on my glasses and I don't know what you're trying to buff out. A good rubbing compound from your local auto parts store may just be your best bet in price and function.