Hmmm @ Thalinor...didn't know you had to have a certain number of posts to give your opinion or post your experience with a screen protector...
Anyway, I too have used the IS on several devices prior to my Storm with great success. I have been happy with their products since I began using them a few months back.
I applied my IS to my screen (only), let it dry overnight with the battery out, and haven't had a problem with it yet. I think they are way more durable that the protectors that Verizon sells. I have never heard of adding a screen protector to a device voiding any warranties.
Anyway, that's my post - and experience - be it one with fewer posts than required by Thalinor.