There really isn't too much to do near the airport, SR 436 (Semoran Blvd) goes north, with lots of strip shopping centers and a few chain restaurants, but not much else. International Drive and the rest of the tourist area is around 30 minutes to the west, I'm not sure that there is a lot to do interesting in the time frame you have.

There are some mini-golf places, outlet malls, a variety of restaurants, and here is a site with various other possibilities:
http://www.internationaldriveorlando...ways/index.asp

Weather wise, Sunday is going to be the coolest day we have had for the past 6 months, with a high of 72, and lows around 54. Today it is around 15 degrees higher. If you just want to get outside at the airport, you can go to the top of the terminal top parking deck, or either outlying garage, there is certainly nothing else to walk to outside.