When we moved from the lake to our new house in the country, one of the first things I did was go around and change over every light bulb in the place to compact fluorescent light bulbs (CFLS). CFLs look like a Dr. Seussian solution to lighting, but in reality they are taking a big bite out of electricity use. They are very energy efficient, and are a perfect example of real world green technology that is here right now.
They do have one drawback, which is the Whoville sized amounts of mercury that makes those cute little puppies tick (or glow as the case may be). I recently wrote an article for Environmental Health Perspectives about efforts to understand the mercury in CFLS and better ways to capture it in case bulbs break.
Long and the curly of it, open a window and leave the room where the CFL breaks. When you come back pick up everything you can and put it in a glass jar (plastic bags leak mercury), plus try to have kids or pregnant women avoid the room.