I think some people, as peetza mention, are missing out on the true power of today's cell phones. So much more than texting or making phone calls.
I rarely use a computer for entertainment any more.
There's a myriad of apps perfect for the outdoorsman, many are free and most are reasonably priced.
I don't think it's wise to trek into the wilderness, many times in the winter with possibly unpredictable conditions, in pursuit of dangerous animals, without having a phone or turning it off. (Yes a deer can be very dangerous).
The iPhone I have will last for a couple of days if I don't play on it too much.