You can search for "Antiglare Touch Screen Protector" in Amazon and some suitable products will appear.
Why would you do such atrocity and how can you really keep clean a non-smooth surface which you constantly touch with your fingers are two issues that I better not think too much about.
But then you don't have the option of a matte screen. And that is essential for me.
I am waiting for the day we have matte touchscreens.