I just came across a great initiative called Lights Out America. It's an attempt at organizing an hour of only essential lights being on in cities across the US, and for every household to install at least one Compact Fluorescent Lightbulb. The organization behind it just did something similar in October in San Francisco, after over 2 million Australians turned off the lights for Earth Hour in March.
The plan is to turn off all non-essential lights on Saturday, March 29, 2008 from 8:00-9:00pm, and for every household to install a CFL bulb.
Sounds like a good plan. Even if your city isn't signed up (so far only 11 large cities are listed), you can still participate as an individual.