Have an energy audit
Not as painful as another type of audit. Visit hes.lbl.gov to conduct a self-directed energy audit. You'll get immediate and realistic information about what you can do to make your home more efficient. For more through, in person energy audit, check out www.hometuneup.com to see if there's an inspector near you. They can come in and check for air leaks, see what areas of your home may be under insulated, and recommend some quick fixes to lower your energy bills.