The Cowon S9 has a nearly scratch-proof screen, but like every other touchscreen player is a magnet for fingerprints. A check through http://www.sgpstore.com/ found this high quality LCD Protection Film for my S9. The feature that stood out was "Anti Fingerprint". My order arrived within a couple of days, and so far I'm impressed with it's anti-fingerprint ability.
The package contains two protectors, a cleaning cloth, and a plastic squeegee. Application is easy, but you have to make sure your screen is clean. A spec of dust is enough to make a visible bubble beneath the cover.The film is a perfect fit, covering the entire front glass of the S9. It is translucent and not transparent, but photos and movies are only barely affected shining through the film. There is a little optical downgrading, but no more than the effect of a fingerprints covering the screen. It's not perfect, but after a few hours of tapping my S9's screen there are no discernible prints on it. You'll still need to clean it occasionally, and keeping your hands clean is advised. With this screen protector those ugly splotches from each tap won't both you again.