This is in reference to this thread from a year and a half ago. DO NOT resurect threads more than six months old! Glenn
I have a 17" iMac and to clean the screen I brush on a generous amount of muriatic acid then rinse it off with a pressure washer.

Sorry, couldn't resist...
Actually, I recently purchased a product called "Monster ScreenClean" (kit with the cleaning liquid and a lint-free cloth) and even though it says that it doesn't contain alcohol and ammonia, I'm still weary about trying it. It was recommended to me by a tech at Future Shop, he told me that this is all they use on their customer's displays.
Sorry for the above pun,
Gemigene