I just ordered a Day/Vue screen cover from this site http://www.nushield.com/dayvue_technology.php. Frankly, I have no idea whether or not it will work, but for $10. or so what the heck.
I use DayVue screen covers. I manage a bunch of Motorola Handheld computers at work and a big complaint in using these was they were hard to use in daylight of Texas sun. I was able to find the DayVue screen covers by NuShield and problem almost went away. I use them on my phone, Canon camera and other stuff with a screen also now and they work great. They are not perfect, but do 100% better with cover than without.