The touch screen is what creates the glare. The 300 has a slight glare when viewed at some angles, but that's about it. I have a 505 which has the same screen as the 300, and I rarely see a glare.
One suggestion: if it's shut off, try and get some fingerprint marks on it to dull it. Weird solution, but it might help. I think there's some touch screen protectors out there that supposedly help, but I don't know much about that.