For protection from the keyboard, I use the foam that came with mine. You should be able to get some at places like The UPS Store, or anyplace that sells any type of moving stuff.
Or do you mean the clear screen protectors, kind of like the ones that are used on pocket PC's and Palms? The only thing like those I've seen for laptops was a privacy screen, and glare reducer.
I just looked in Google and the only one I could find like that was for a 12 inch Mac. And the ones for desktops of course.