Straight from the Dept. of Who Knew? comes news that your iPhone includes a moisture detector that tells you if the little slab of delight has been dangerously immersed in water, chicken soup, fruity cocktails, whatever.
So if you're buying a used iPhone and the little indicator dot at the base of the headphone jack is anything but pristine white, you'll want to ask the seller if he's forgotten to mention any unfortunate swims.
How to tell if your iPhone has liquid damage [iPhone Atlas]
