I've been keeping my ixus300 in various pockets and other unprotected places, and its LCD never got scratched, at least not in any way that bothered me.

My feeling about portable gadgets like cell phones, MP3 players, and digital cameras is that they're meant to be used, and that means getting scratched sometimes. I don't mind if there are some scratches on the casing or LCD. So I don't bother with protectors or bags for my portable gadgets.

The convenience of being able to yank it out of my pocket and take a quick shot is more important than whether the LCD is pristine. In fact, that's the same reason that the form factor is so important to me, and the same reason I want a quick response time. That means more chance I'm going to have the camera with me when the opportunity for a shot comes, and more likely to get the shot because I'm not fiddling with a protective case.

(The wrist strap, on the other hand, has saved me from losing or seriously damaging the camera numerous times, so it stays. Well. Except for the time that the mounting plate that holds the wrist strap came unscrewed. That was a scare.)