Here's a great tip for the upcoming winter months.

Beat Frost
Run the air-conditioning while defrosting the windshield. (New cars do this automatically, but in older cars, turn it on yourself.) AC air is dry, so it will take the moisture out of the air by dehumidifying as it cools. If you're cold, adjust the temperature so that the AC pumps out warm air.

Courtesy of http://bit.ly/QNuY9t