Some things should be built tough! because you never know what life is going to throw at you.
I have replaced many mobile phones over the years because they just do not put out.

Cold, Rain, Drunk and disordely and the occasional dunk in the ocean is a selection of what usually shuts them down.

Enter the Sonim XP series of phones. http://www.sonimtech.com These are mighty tough phones (and with a 3 year unconditional guarentee) theres not much that will damage them. I first had the XP3 and then upgraded to the XP3.20. The XP3.20 is a more bells and whistles model with 2mp camera, bigger screen and other stuff.
The phones are tough.... but the other week it stopped working, dont know why but some of the buttons stopped working. After 2 or three email exchanges with Sonim, they sent me a RMA number... And a DHL account number. Free shipping!!! I am suitably impressed.

My new phone arrived in 4 days and I am very happy again. Even more happy than before because I feel comfident in the commitment Sonim have made to their customer.
I highley reccomend the XP3.20 to anyone that works or plays anywhere the environment might play games with you.
Mine Broke... but in the real world things do break, but the 3 year guarentee ment only minor inconvienance.
3year unconditional guarentee, IP67, 2mp, GPS... Sonim XP3.20 Quest

Bullet proof (almost) look at the back, 2 screws to secure the back cover and another holding the USB cover in place.