Kudos to Mark, first of all, for pointing out that flourescent light bulbs can be a great way of saving electricity. Some other ways:
If your wife works, calculate how much she really takes home, and consider whether she's working to support your family, or whether she's working to support daycare centers and the government.
Consider putting in some more insulation in your attic, or when your siding needs to be replaced.
And finally, develop the habit of turning things off when not in use.
But whatever you do, don't buy a hybrid or flex fuel vehicle until you've implemented a few more basic suggestions. It just won't pay.