If you need to make late summer or early fall travel plans, than this code is for you! 
http://www.southwest.com/cgi-bin/buildItinerary2
At the bottom of the page there is a spot to add a promotion code.
Enter PROMOTION CODE: DING15
Terms and Conditions:
http://www.southwest.com/cgi-bin/buildItinerary2
At the bottom of the page there is a spot to add a promotion code.
Enter PROMOTION CODE: DING15
Terms and Conditions:
- Purchase must be made between April 18, 2008 and April 21, 2008 for travel August 23, 2008 through October 30, 2008.
- Blackout dates apply August 29, 2008 through September 1, 2008. If any portion of travel falls on a blackout date the discount will not apply.
- 15% discount valid for use at southwest.com off the total amount of roundtrip purchase before taxes and fees.
- The discount is only valid with the provided Promotion Code and is not combinable with other Promotion Codes.
- This promotion does not include Business Select, Business, or Senior Fares.
- Discount does not include taxes and fees.
- Roundtrip purchase required.
- Minimum seven day advance purchase required.
- Changes made to the itinerary after purchase may eliminate qualifications for this promotion.
- Youth, Child, Infant, and Military Fares are not available for purchase at southwest.com.
- Reservations made through southwestvacations.com or swabiz.com are not eligible for this promotion.
