I'm terribly worried about the durability of the new iPhone 4's screen. I want to get a screen protector to protect the screen but I don't want the screen protector to get scratched. Is there a skin or something I can place over the screen protector to protect it? Is there a skin I can put over a case that I put on the iPhone 4? I want my phone and cases to be pristine when it hand it down to my children. Help!!