If you live in IL and have Ameren service for your power company, you can save money by signing up for Power Smart Pricing.
You pay real-time prices for the power you use, instead of the day's average price.
It requires a little more attention to be paid to what you're doing to be most effective. For example, you won't want to do laundry during peak price times in the summer; this could result in your paying more than the average price would have cost.
You can receive peak price alerts via phone or email each day (or not at all). This way you will know when the highest prices are charged, avoid using power-sucking machines like your washer and dryer during those designated times, and have a cheaper electric bill.
Get all the details and sign up at their new website at http://www.powersmartpricing.org/
If you don't have service through Ameren, check with your own power company about similar programs.