The screen is not only a display device but more importantly an input device. So if there are any scratches on the screen, it will affect the sensitivity of the screen. There in turn affect the wirting recognition ability of you palm. You might need to replace the overlay after a while. There are screen protectors you can buy.
Several makers are available.
The more popular one is WriteRight. It is a good idea just to get a simple case for you Palm to protect it. The Palm get damaged easily even it is in you pocket. Copyright 2001 INT Media Group, Incorporated All Rights Reserved.