The current sale from Frontier is valid for travel through March 7, Monday through Saturday. Avoid blackout dates: December 22-23, 26-28 2011 and January 1-3, 7 and February 17 and 20. Tickets require a 14-day advance purchase. Nevermind that Frontier says this sale expires December 15 (a mistake, we're guessing, since this sale was posted to their site just today).

Fares include:

New York to Nashville $204 round-trip

Salt Lake City to Boston $296 round-trip

Denver to Albuquerque $146 round-trip

Milwaukee to Flint $268 round-trip

Austin to Albuquerque $188 round-trip

Omaha to Nashville $288 round-trip

San Antonio to Pittsburgh $328 round-trip

Tampa to Des Moines $268 round-trip