Fluorescent Bulbs
I have to echo this post from Glen Reynolds about fluorescent replacement bulbs for the home. If you have not bought any in the last two years, they have come a long, long way. They are much cheaper - home depot was running a screaming deal on multi-packs here this weekend. The buzzing fluorescent sound is gone. And the ones at Home Depot came in a range of three color temperatures - from warm white, which comes close to matching the light color and temperature of incandescent bulbs, to bright white and daylight. The latter have a brighter, cooler (blue-er) light that you might more closely associate with fluorescent. I use the warm ones indoors and the cooler white ones outdoors. I can barely tell the difference even for bare bulbs in my ceiling cans between the newer warm fluorescent and the older incandescents. And if the bulb is in a lamp under a shade, I really can't tell the difference.
These are a total no-brainer. They pay for themselves in longer life alone, and the 70-80% energy savings comes on top of that. Highly recommended.