Southwest has a 72-hour distance-based fare sale for fall travel. Book by Thursday, June 13 for travel from August 26 - December 18, 2013.
Sale fares are $49 up to 500 miles, $99 up to 1250 miles, $129 up to 1750 miles, and $149 above 1750 miles.
For more details see this thread:
http://www.flyertalk.com/forum/south...e-11-13-a.html