Seemingly old-fashioned conventional phones use only a trickle of electricity, and that comes through the phone line. An added benefit is that such phones will work even if the power supply to your home is cut off in a storm or other emergency. Plus, retro is cool!

Cordless phones use between 2 and 3 watts in both active and standby modes, according to tests by Lawrence Berkeley National Labs. About 60% of cordless phone energy use occurs during standby time.

If you still want the convenience of a cordless phone, consider just having one for your home, and get corded versions for rooms you aren't in as much. The energy savings will add up. Make sure the cordless you do get is Energy Star-rated, indicating high energy efficiency.