At one time I saw a product on the net that was supposed to help fill and reduce scratches on LCD displays. I don't know how well it would work. Also, on all my PDAs, the outer-most layer of the screens is obviously a different material than the hard plastic laptop displays expose. So I don't know how effective a product would be that is meant for a laptop display. You always run the risk of some sort of chemical reaction or similar doing real damage to your display. I have also heard that Armor All is supposed to help fill in scratches, which makes them less noticeable. I have tried this on a scratch on my laptop's display, and it didn't seem to help at all. If the scratch is visible because of light reflecting off of it, then a screen protector may help hide the scratch.
Dan East