“The discount carrier says fares are $25 for travel up to 375 miles. The price is $50 for travel between 375 and 549 miles, and $75 for flights between 550 and 999 miles. A one-way fare of more than 1,000 miles costs $100.

The fares are available for purchase through Thursday, for travel between Dec. 2 and Dec. 16, or between Jan. 5 and Feb. 10. Other restrictions apply.”

Purchase by October 29, 2009, 11:59 p.m. Pacific Time.

example pricing (taken from southwest.com)

From Washington:

• To Austin for as low as $100 one-way
• To Chicago for as low as $75 one-way
• To Dallas for as low as $100 one-way
• To Denver for as low as $100 one-way
• To Ft. Lauderdale for as low as $75 one-way
• To Houston for as low as $100 one-way
• To Jackson for as low as $75 one-way
• To Kansas City for as low as $75 one-way
• To Little Rock for as low as $75 one-way
• To Minneapolis/St. Paul for as low as $75 one-way
• To New Orleans for as low as $75 one-way
• To Oakland for as low as $100 one-way
• To Omaha for as low as $75 one-way
• To Orlando for as low as $75 one-way
• To Salt Lake City for as low as $100 one-way
• To San Antonio for as low as $100 one-way
• To San Francisco for as low as $100 one-way
• To St. Louis for as low as $75 one-way
• To Tampa Bay for as low as $75 one-way
• To Tulsa for as low as $100 one-way
• To West Palm Beach for as low as $75 one-way
  

Travel Dec. 2 – Dec. 16, 2009 and Jan. 5 – Feb. 10, 2010.

www.southwest.com

Taken from Yahoo News