splash Masque Clear Screen Protector for iPhone 4 4G  4S AT&T and Verizon (3-Pack + 2 Bonus Back Films)
Admittedly, it took me all three of the included protectors to get it right (apparently my office has a lot of \\"stuff\\" floating in the air), but the final result is perfect.  I cannot discern any visible difference between the unprotected and protected screens.  It is, however, a lot more obvious that the screen is in place when I'm trying to swipe or scroll.  Maybe this will be less obvious as the protector gets dirtier or I become more used to its presence.    Overall, though, so far so good.