Isn't this already in the current iPhone? it's a little plate that changes colour inside the headphone jack....

http://www.iphonebuzz.com/iphoneipod-touch-have-water-seals-on-them-171643.php

Most phones do this already.

Sony Ericsson and Samsung phones have it on the battery, with the SE ones also inside the phone in a visable place. Some Nokia handsets have them visable, and most motorola phone hsav ethe under the battery as in the apple "pattent". Most start life out as white, but then turn red when they have become wet.

Also, most water damage, at least on phone, will show up with corrosion on the PCB, an usually blue/green corrosion on any copper contacts.

This technology is already in use, my NOKIA 5210 has a water sensing sticker.

As Suf said this is already in the current iPhone. Has been since launch. Apple techs have a little viewer that they poke down the headphone jack socket to see it.

You guys need to keep up.

All that.. and Apple tries to patent it when others already have something similiar. As always, Apple can't come up with any original ideas to patent.

I don't think this is new, even the Nokia 3300 turned permanently green once it had been wetted.