You can sign up for the frequent flyer program at Southwest (no need to have a flight and it's free). Print out your card with your name and number and bring it with you to the ticket booth. You will get 20% off on adults and kids prices....just did this last week with no problems...it saved us a total of $35.00!
Not sure if this beats the AAA discount, but at least you don't have to pay to join.