I've noticed the moisture sensor behind the battery door when I've (inevitably) had to do a battery-pull reset.
Question is, what's it show when its got wet? I'm sure mine never has, and the phone runs perfect, but wondered what it looks like when it's been "activated"? (Conversely, what's it look like when it hasn't? I have a suspicion mine shows "wet", but I know it never has been.)