http://www.parkbluesky.com/promo/holiday. You can get additional coupons at their site, http://www.parkbluesky.com/rates. They are located on University and the 143, on the South side of the airport and promise to get you there faster than the airport can. Reservation rates are $7.50 for uncovered parking, $9 for covered parking. Save big!
To get three free days of parking in January or February, go to http://www.parkbluesky.com/promo/3free.