Recently I've been trying to figure out what makes my home office so very hot.
I went around and plugged the Kill-a-watt into all the devices. Two worst offenders: halogen torchiere (250W) and CRT monitor (150W). Two servers in the closet are using less power than the CRT. The halogen is the clear heat offender, though.
I did some reading on CFL's (Compact Fluorescent Lamps). Apparently they've come a long way in 5 years. I didn't like fluorescent bulbs before - they flickered, the color temperature was really off, and they weren't dimmable.
But all these things have changed in the latest versions: you can get CFL's that have electronic ballasts (so they refresh hundreds or thousands of times a second, not 60), bulbs in 2700K or 3000K rather than 5000-5500K (more like halogen color temperature), and GE and others even make some bulbs that are dimmable (without noise or flicker). The best fixtures have all these features available.
The metric commonly in use seems to be lumens/watt. So an incandescent bulb will produce 10 lumens/W, a halogen will produce 20, and a CFL can produce up to 80. (Halogens give off 90% of their energy as heat.) And worse, most dimmers make the situation worse - a halogen will produce 2 lumens/watt once dimmed.
I ordered some lights from Full Spectrum Solutions, since they look like they're pretty reasonably good at this. Will write more once the order comes in, and see if the CFL's are generally more tolerable than their tube-fluorescent predecessors.