Jim, depends on the model and what the material is on the front.
If you have a solid front screen, it may be a replacable part. You may also be able to use that stuff that fills in scratches on glasses if the material is a solid surface (but I am not sure).
If it is a soft LCD material screen, I am not sure that anything will truly do it...
you might want to try:
http://www.google.com/search?q=scrat...en-US:official
some of these have some ideas (including vaseline, and I am sure you have some of that in the house) that can possibly make it look better (but not fix it).
When in doubt, call the manufacture service line
Alex