I have been a ham for 15 years (since I was 17) and my primary application of the hobby has been back country communications in Arizona. I am active with a local 4x4 Ham radio club and the ham radio is our primary form of communications. When hiking / camping / and kayaking, I always bring my waterproof Yaesu VX-7R with me and can usually communicate with a local mountain top repeater if I have a clear view. It sometimes requires hiking to a higher elevation, but typically works. Sometimes, especially when I am on the Mogollon Rim, I even have access to a telephone autopatch and can telephone my wife from my handheld ham radio to check in with her.
My mobile radio is capable of functioning as a make-shift repeater (crossband repeat) and on most excursions, I am rarely more than 5 miles from my truck. As such, I can actually use my truck to significantly extend the range of my HT (handie-talkie). However, I typically only do this in more remote areas where I know that I will have a difficult time communicating with a repeater.
Additionally, I use APRS in my 4x4 to beacon my GPS position. Some handheld and mobile radios have this feature built in. The end result is that friends, family, and other hams can see my exact position on a Google map overlay.
Finally, one of the most important reasons for bring my radio on every trip is that I also know that should I ever overstay a planned trip in the back country, my wife would inform the local search and rescue teams that I am a Ham and that I would be trying to communicate on 146.520 at the top of every hour. This would significantly increase the probably of a successful rescue, should I become lost or injured.