I live outside of Tampa, Florida. So really hot, and crazy sticky awful humid: check: got both!
We keep it set at 82 during the day, and turn it down to 79 at night, with the ceilfing fan on medium when we go to bed.
Our house is made of cement, and it is well -shaded (for the most part). I also line dry all of our clothes and rarely use the oven, so that helps to cut down on accidentally heating the house. When I get warm while cooking, I just drag our upright fan to the kitchen and it works great. We also use compact flourescents, and turn the computer off whenever we aren't using it. ETA our house is about 1000 sf.
I am convinced you can acclimate to the heat. Our a/c went out a few weeks ago (before it got hideously humid) and with the fans and tank tops and shorts, we were ok. I was glad when it was fixed though!
I am, however, mericless about using as much a/c in the cars as I want to!
Even so, I often need to take a quick, cool shower right before bed.