Someone posted something similar to this a few months ago and I could not find it. All of the sudden - literally 2 days ago - my 3GS is almost impossible to wipe clean. I have tried to different microfiber cloths (I know they sometimes get "build up") and even used a towel (which worked pretty good), but the screen smudges up easily and is hard as heck to clean off. Used to be very easy but something has changed. Maybe my body oil?? Has anyone else experienced this?