This week I was able to borrow a Kill A Watt meter from our local library. It's pretty nifty - you plug it in, and then plug different electrical items into it (lights, appliances, computers, etc.). It tells you how much electricity each item is using when it's on, and also when it's plugged in but just sitting there unused (so you can measure the "phantom load" on your system).
My engineer husband has been having tons of fun figuring out which appliances we should definitely be unplugging when they're not in use (like our copier/printer/fax, which so far (even though it puts itself in "sleep" mode) has about double the phantom load of anything else we've measured in the house!) - and which we apparently need not unplug (like our lamps that are on wall switches, which have zero phantom load as long as the wall switches are off).
Right now, our refrigerator is plugged into the meter. We're leaving it there for 24 hours so we can get a good picture of how much electricity it is using, and whether a new refrigerator is in order or if the one we have is still running "typically" in terms of energy usage.
I'm sure our electric bill will be a little higher than usual this month, on account of the handful of Christmas lights we have up outside - but I'm hoping the "phantom load" exercise will help us bring the bill down as we head into 2010.
I've read that many libraries are starting to have the meters available for borrowing - might be worth looking into if haven't tried one yet, and you're curious about energy usage at your house too!