A smart phone generally comes in 3 flavors, Droid, Iphone, WIndows 8. A Samsung phone uses Droid software, just modified (Droid software is made be Google, and is considered open source or people can do with it what they want). It is a solid platform, more popular in sales than Iphone. But it can get some bugs as the quality control of the software offered is vendor predicated. Iphone is a mac based phone, very popular. A solid platform but an expensive platform. Windows 8 is new. Reviews have been positive. Applications have been slow in coming, and it does not play well with any system outside of a Windows 8 system.
I am a mac guy, very computer savvy. But I like my Droid. I have a motorola RAZR MAXX which I bought at a time when battery life was uber important to me.
Most expensive new phones (Motorola Droid RAZR and above, Samsung Galaxy, Windows 8 phones offer a certain level of water resistance. as well as drop resistance. Not much crush resistance.
Generally getting splashed with a hose is about as far as an unprotected modern phone can go. Forget submersion. Screens tend to break on all the phones. Mine has gorrilla glass, but I welded next to it (my phone was in my pocket) and the slag pock marked the screen.
On Amazing Race, we were provided otter boxes for our phones and pads as the gear took a beating. The screens came back scratched to heck but the machines still worked. Many reports of them being taken for a swim. or being dropped from great heights. But, a smack on the screen and it was all over but the crying. BUT these protective covers add weight and size, and a certain level of stickiness that makes them hard to pull out of your pocket.
So in conclusion, put your hand on all three softwares, find the one that fits you the best (if you are technically challenged, probably the Iphone is your best choice IMO - If you are computer savvy, a droid. If you are a risk taker on something brand new out of the box that looks pretty cool, Microsoft)). Buy the latest models (probably $200 to $300 with credit from your mobile company). Get yourself a protective case, but know what you are buying when you do (just don't settle on the one that is pink cause your wife likes the color). Make sure it covers your concerns.
In the end, either you will loose the phone or loose it to a cracked screen (which can be replaced now adays for around $100). Not much you can do when you are climbing into the tractor, it drops out of your pocket and you drive over it with some ground turning implement or a brush hog running full bore.
Hope my opinion helps.