I once had a roommate borrow my cell phone while she had a cold. She felt bad about this, so before she gave it back to me, she took it into the bathroom... and I heard the sound of the sink running. Sure enough, she handed it back to me dripping wet, with all the brokenness that implies. On parental advice, I took the battery out and left the rest of the phone balancing in some weird position for maximum surface-area-to-air exposure, and let it dry for a day or two. It worked again, perfectly.