I hate ZAGG screen protectors. I've heard of glass screen protectors before but never tried them myself. I've heard of two different glass screen protectors, SGP and Spectre. I'm still waiting for more reviews on Spectre because they are available 8/3 and the SGP one is available now. I Wanna see which reviews are better before buying because for a screen protector, they are pricey.
Spectre - Spectre for Samsung | XGearlive
SGP- SPIGEN SGP | iPhone Cases | The new iPad Cases | iPad 2 Cases | Samsung Galaxy 3 Cases | Screen Protectors
Oh, but of course, I don't know if these will be available for a lot of different phones. Pretty sure they have ones for iPhones since they're so popular but don't know about DROID 4.