Until midnight ET Dec 22, Spirit Airlines is offering up to $35 off roundtrips. Enter SAVE35 (all caps, no spaces) in the Promotion Code box on thehome page
when booking your flight to save $35* off your roundtrip purchase for travel from January 5, 2009 through November 11, 2009. $9 Fare Club members will receive the full $35 off, non-members will receive $17 off. Everyone always gets $5 off each way when booking on Spirit's site (except to/from Detroit).