In an effort to reduce lighting bills and cut energy costs, more and more homeowners are installing "occupancy sensors," devices that automatically turn lights on and off in response to the presence of a person or people in a particular room.

Most occupancy sensors work in response to motion or sound: infrared sensors actually detect the infrared radiation -- also known as body heat -- that people naturally generate, and turn lights on or off depending on whether they detect infrared radiation in the space where they're installed.

Occupancy sensors are generally installed on ceilings or walls and come with a controllable switch so that they can easily be deactivated if necessary.

However, the "old" way of reducing electricity use still works:

• Turn off lights when leaving room.
  Get into the habit of always turning off the lights, even if you are only going to be away for a short time.

• Use low wattage bulbs to save energy.

• Install compact fluorescents.