Brrr... It's cold! Time to stuff a few more dollar bills into the furnace and fire it up.

Or not.

There are some options out there that can lower your heating and other energy bills. And, if you hustle, the federal government will pay you to make some of those moves.

Homeowners have until the end of 2007 to take advantage of a one-time $500 energy conservation tax credit. (Some business energy tax credits were extended in the closing hours of the Congressional session, but these were not among them.)

To take advantage of the credits, you have to buy something big, like replacement windows and doors, a metal roof, a new high-efficiency heating system or water heater.

Typically, you'll get up to 10 percent of your expenses back in a tax credit, but other conditions apply. In some cases, such as the roofing, you'll get credit only for the materials, not the labor required to install it. All of the materials and systems have to meet various requirements; you can find details at the Energy Department's conservation focused Web site, http://www.energystar.gov.

There's a separate federal tax credit for folks who go solar. Install a solar electric system in your house and the government will give you 30 percent back, up to $2,000.

If you want to get serious about energy conservation, it's good to start with a baseline. Many local utilities conduct inexpensive home energy audits; you can also contact the Residential Energy Services Network (http://www.natresnet.org) to find a professional rater who can do a "blow test" of your whole house to find air leaks.

That test could set you back a few hundred dollars, but it could point the way to moves that would save more than that. Savings on big ticket items — insulating your house, upgrading the heating system and the like, can be huge; more than $1,000 a year. And those savings are likely to pay off more and more as energy costs continue to rise.

In the meantime, here are some quick and easy ways to save immediately on your energy use. Find more at http://michaelbluejay.com/electricity/, an excellent Web site that includes a calculator which will enable you to figure out exactly how much each appliance and lightbulb is costing you, and how quickly your savings could pile up.

— Turn down the thermostat at night. If you can go a full 10 degrees for eight hours, you can save 15 percent on your total fuel bill. Leave your house at that temperature when you head out to work in the morning and save twice as much. If that's too cold, try for eight hours, five degrees cooler, and cut your fuel bill 10 percent.

— Ratchet the heat back on your hot water heater from 150 degrees to 120 degrees and save roughly $160 a year. Your body temperature is 98.6; it will still feel warm enough.

— Every light bulb that you switch from traditional incandescent to fluorescent will save $30 a year, according to the California Energy Commission.

— Save $150 a year washing your laundry in cold water instead of hot. It's easier on the clothes too.

— Put your computer to sleep when you're not using it, and switch out your old CRT monitor for a new LCD one. You'll save about $85 a year.

— Air dry your dishes by simply leaving the door to the dishwasher open after it's done washing and save roughly $22 a year.

— Buy efficient appliances. You can find ratings for many appliances at the EnergyStar Web site.

— Remodel wisely. If you're getting a new roof, get a light color, so it reflects sun and heat. Install shade trees, even if it's some subsequent owner who benefits from the energy savings.

Plug openings around electric outlets, windows and doors with caulk or self-stick foam insulation.

It all adds up.