In addition to adjusting the thermostat of your air conditioner and using fans, another tip to help combat the heat and save energy (and on your bill) is to use heat control window film. Very similar to the kind you use for your car, these films are readily available at the hardware store, and are simple to install. Over the weekend, we put up some by Gila to cover my bedroom window, which gets all the afternoon sunlight, and makes the room unbearably warm.
Gila films come in two "shades" for heat control: platinum and light. The Platinum will reflect up to 70% of the summer heat, and during the winter, will retain up to 55% of winter heat. I opted for the "light" version, which reflects up to 55%. Even while putting the film up, we noticed a big difference. As the sun was beating down through the window, whenever we were behind the film, we could feel the glare was much less intense. Installation simply consisted of spraying on a solution and using a squeegee, although if you have a larger window, it helps to have a friend to lend a hand. We got ours at Home Depot, for $39.99 for a 3ft x 15ft roll. Has anyone else installed these?
(Re-edited from an original post dated July 31, 2006)