Many regional power suppliers offer rebates for reducing electricity consumption during periods of peak demand.
Cost: Washing clothes and dishes at night during non-peak hours, and turning the thermostat up or down a couple of degrees during a cold snap (or heat wave).
Savings: $25 to $50 per month on your energy bills, depending on the season.
Bonus: You're easing the strain on the power grid--and lowering the odds of a blackout.