Replace light bulbs. Compact fluorescent bulbs use 75% less energy and last ten times as long as traditional incandescent bulbs.
Add insulation. Keep the heat in this winter by adding insulation to your attic.
Install a programmable thermostat. A thermostat only takes a couple of minutes to install, and can be programmed so you are never uncomfortable.
Use a special paint. Mix a nontoxic ceramic powder into your paint to reduce the amount of heat being passed through the walls.
Protect your pipes. An insulating wrap can keep pipes from freezing, and keep hot water pipes hot.
Redirect the heat. Move the fan's switch to reverse so the blades run counterclockwise and push the hot air down from the ceiling.