Waterproof Cell-Phone Cases

Here's the Dry Pak phone case I use:

Cell-Phone Case

I've also heard good things about the AquaPac brand of cases and used them in the past:

Aquapac Case

I almost always take my phone sailing.  I've been able to call home to let Sue know I'm running late.  If broken and I can't get home I've got a way to call for help.  Fortunately after nearly 30 years of sailing I've always been able to get back in.   But, just in case, with the phone I have the option to call.  

When you put the phone in the bag, whatever bag, give it a hard squeeze to make sure it's water tight.  I carry the phone around my neck under my lycra or wetsuit and I don't even notice I've got it.  Avoid having anything sharp near the bag as it could poke a hole in it.  You can use the phone while in the bag, the sound goes right through the bag and works great.