Way to remove or minimize iPad/iPhone 4 glass scratches?

My new iPad has a scratch that produces a rainbow effect on the screen. I have read that cerium oxide can be used to reduce the appearance of scratches on Gorilla Glass which is similar to the iPad/iPhone 4 glass, but it is hard to find step-by-step instructions on how to use it or any examples that it works. Does anyone have any experience removing scratches using cerium oxide or something else?