Cell or not to cell

I don't have a cell phone. The only way you can reach me is the phone at my parents' place. But lately, I,ve been thinking about buying a cell phone. I don't really believe in the idea of a cell phone, but here is the reason.(Some of you might ask why I don't believe in them it's because I've seen so much kid having one and cannot even manage it, and I don't like being disturbe when out of the house!)
But here is why:
-My job is an on-call thing. They do call me when someone is sick, have an appointment or has some course(don't remember the real term). I usually get call during the evening. And like most of you know, I'm during karate 3 times a week during that time. And it is usualy the time that they call for work. That would be usefull to them to reach me everywhere(and maybe more$$$$ in my bank account!)
-I do travel a lot by myself, sometimes at night, sometimes on big distance. I'm 26, 5foot3 and 160 pounds. Pretty much anything can happen to me! If my car breaks(it's an 1999 after all), I cannot reach anyone. And even if I'm use to it by now, my gas gage doesn't work well!
So what do you think? So should I get one or not?