Suffering from dreaded "scratched lens cover syndrome", I took my iPhone 4 to the local Apple store. I made an appointment with the Genius Bar and twenty minutes later, I was helped by a Genius: Explained that I noticed foggy pictures, especially in sunlight. Noted that it appeared my lens cover was very scratched, but there were no scratches elsewhere on the phone. Noted that I heard Apple stores are able to replace just the back cover plate. Employee cheerfully confirmed. Ten minutes later, I had my iPhone back with a new back cover. Five minutes after that, I had my iPhone again in my hands, after the employee removed the inside plastic. After I got home, I removed a third piece of plastic he had missed, one that covered the inside of the lens cover. Now my iPhone 4 is as good as new. I was not charged and the employee was extremely helpful and pleasant. Thanks, Apple.