We're guessing you've already started. You've probably changed all the lightbulbs in your home to energy saving compact fluorescents already. You're saving the environment as well as saving money on your electricity bill.
Now we want you do something for someone else. Maybe it's a friend who hasn't gotten around to changing their lightbulbs yet, maybe you know an older person who can't easily reach high up light fixtures. Whoever it is, help them out by changing at least one of their bulbs.