To Michaelp.  
I'd like to weigh in on this one, even tho I just joined.  I have both the iPhone 5 and the 4S, myself.  For what it sounds like you're going to use it for, I don't think you'll notice a huge difference.  Especially if you are upgrading from a flip-phone now.  Sometimes I even prefer the smaller, more compact size of the 4S too.
If price is the main issue, I would get the one that is cheapest between the two (depending on your carrier and plan, etc.). If you can get a used 4S for a great price, I'd go with that one for sure. In my opinion, of course.