Long story short here:
If you own an iPhone, Apple’s warranty will often be very liberally applied by Genius Bar employees if you’re nice to them…
…unless the submersion sensor has been tripped.
“What submersion sensor, Nathan?”
Well, funny you should ask. There are actually two submersion sensors inside an iPhone: one just inside the iphone jack port (the wide narrow thing on the bottom that you plug the USB cable into), and one inside the headphone jack. To see them, you need a magnifying glass and a flashlight, much like your doctor uses to look into your ear canal. The sensors are just little strips of moisture-sensitive paper: if they get wet they turn bright red. (Pictures here.)
Here’s the catch: you don’t need to drop your iphone into a toilet bowl (or fishtank, or river) in order to trip the sensor. In fact, you don’t need to submerse it at all. Just a few drops of water that creep in at an unlucky angle are enough to do it. If that happens, your warranty is null and void, and no amount of sweet-talking will change it: Apple will refuse the return of the phone, and they will charge you two hundred dollars for a refurbished replacement.
You can buy a little silicone insert for the iphone jack for $6 from various websites. You may wish to consider doing so.
Why yes, I do speak from highly annoyed experience here, why do you ask?