Waterproof your iPhone
Did you know that you can put your iPhone inside a plastic bag and still use the touchscreen? Yes, that’s right, stick your iPhone in an airtight ziplock bag, and you’ll have an instant and amazingly cheap waterproof case for your iPhone.
The context of this tip is actually in regards to cooking, First & 20 suggests placing your iPhone inside a ziplock bag so you can keep using it in the kitchen with dirty hands, not a bad idea at all, but the uses for this extend far beyond the kitchen… imagine the possibilities with a waterproof iPhone! Paint your house without painting your iPhone! Browse the web from the bath! Update Facebook in the pouring rain! Text your friends from the depths of the seas! Well, maybe not that extreme, but you get the point. This is a rather funny tip, but it’s actually really useful and I’ve already found myself using it a few times around the house. Obviously you should make sure the seal on the ziplock bag is very strong, or else your iPhone will drown.
[ via First & 20 ]

Underwater pictures ? ^^
I’ve been putting electronics in ziplock bags for years as a quick and dirty water-RESISTANT protection when going into wet environments or out in the rain. I’ve even taken phones in the shower stall that way, but I’m not sure I would trust my $500 iPhone’s life to a $0.01 plastic baggie in terms of intentionally submersing it in water for photos. Too risky that cheap plastic might rip or the ziplock seal isn’t quite as sealed as you thought. I wouldn’t call this method water-PROOFING.
Works great at Six Flags. Never had any moisture get in after drenching rides like Thunder River, Log Flume, etc.
Errr, actually, it would loose signal underwater.
that’s funny because…
http://www.youtube.com/watch?v=Ws4OFFmBU4s
Im doing this trick in the bag right now. I knew about it before but last time when I was using it the bag broke and just a little water came in. If you get really strong bags they probably won’t rip (I used ziplocks small bag so it fits perfectly to the iPhone) but today I true rapping in plastick rap and then put the bag for extra protection, with both I then on you can still use the touchscreen. I would not trust my phone to actually go directly in the water but if it does i think you will be ok