Compact fluorescents

You probably already know some of the advantages of compact fluorescent bulbs. They use far less electricity for the same amount of light, so while they cost a little more, they'll easily save more than that over their lifetimes. And they last a lot longer. All that means less cost to you, and less environmental impact on their manufacture, distribution, and disposal (though some of that last factor is eaten away by the fact that they're harder to dispose of safely), as well as the environmental impact from the energy that makes them glow.

When your light fixture is hard (or at least non-trivial) to get to, like a ceiling-mounted one, the fact that they last 5-10 times longer starts to add up to another advantage, too. This is especially so when the fixture is really a pain to reach, like the overhead lights on the cathedral ceiling of my great room, which are about 14' off the ground, and inside glass globes. My ladder, fully unfolded, just barely can get me up there, and it's nerve-wracking to climb up every time. So the last thing I want is to have to go up there every six months.

There's one advantage that might not have occurred to you, though. Most lamps have a maximum safe wattage. This could be because of the electrical wiring, but it's more likely to be because of heat. That's the case for those great room ceiling fixtures: the glass globe can't safely play host to lights with more than 60W before there's a danger of the heat building up inside that glass globe and causing such dangers as broken glass, electrical problems, and even fire. 60W might seem like a lot, but when it's 14' off the ground, and illuminating a large area, it's not very bright. They are conservative in their estimates, and many people put 75W or even higher into those fixtures, but it's not safe to do that in the long term.

Compact fluorescents provide a perfectly safe and acceptable "loophole" to these rules, since a CF bulb that gives off the equivalent of a 100W light is only about 24W. So it's more than safe in a fixtured rated to 60W, since it's really only drawing 24W of power, and only generating approximately as much heat as a 24W bulb would draw, even if it's giving off as much light as a 100W incandescent. (Not exactly, but near enough.)

Since there are now CF bulbs that are dimmable or three-way, and which come on pretty much instantly, and which produce a very natural tone of light devoid of the "flicker" that the long tube designs create, and which only cost around $10, there's not much reason not to start using them. We've been replacing bulbs with them as older incandescent bulbs burned out, and most of the bulbs in the house are now CFs, except the ones in specific shapes I can't yet get as CFs. Gradually I intend to switch everything over. Today, I replaced the bulbs in the great room overhead lights, and I'm very pleased with how the new 100W-equivalent bulbs are working.

Can't wait for the next generation that's coming, LED lights that use even less energy, produce even more natural-like light (more so than even incandescent), and last even longer. They're saying we'll have those ready for our light fixtures within a couple of years. So by the time these CFs are dying, I'll have a whole new generation of lights to replace them with.