http://en.wikipedia.org/wiki/Southwest_airlines
Southwest does not use the more traditional "hub and spoke" flight routing
system of most other major airlines, preferring instead the "Point to Point"
system.
Focus cities:
Baltimore-Washington International Thurgood Marshall Airport
Chicago Midway International Airport
Dallas Love Field
Denver International Airport
Hartsfield-Jackson Atlanta International Airport
William P. Hobby Airport (Houston)
McCarran International Airport (Las Vegas)
Lambert-St. Louis International Airport
Los Angeles International Airport
Nashville International Airport
Oakland International Airport
Orlando International Airport
Phoenix Sky Harbor International Airport
San Diego International Airport
