Can anyone recommend a good water proof case for iphone4? I am not looking to go swimming with it or anything but am off doing some mountaineering and need a well built weather and splash proof case. I saw the griffin survivor and whilst it looks tough I can't see anything about it being waterproof. Has anyone got one and do they know if it protects from heavy rain and possibly being dropped in puddles etc? I prefer hard cases rather than the bag style water proof cases. Cheers.