This is from the SWA website -- all their planes are Boeing 737's with slightly different configurations (some have more seats, but most of the ones we've flown are 3/3)-----
Fleet:
Southwest currently operates 453 Boeing 737 jets (as of April 25, 2006).
Type Number Seats
737-300 194 137
737-500 25 122
737-700 234 137
The Companys fleet has an average age of about 9 years.
The average aircraft trip length is 617 miles with an average duration of one hour and 45 minutes.
Southwest aircraft fly an average of seven flights per day, or about 12 hours and 45 minutes per day.
Southwest was the launch customer for the Boeing 737-700 in 1997. Southwest was also a launch customer for the Boeing 737-500 and -300 series aircraft.
Southwest is updating its traditional gold, red and orange paint scheme by adding canyon blue. All new aircraft will have the updated colors and interior. Existing aircraft will be retrofitted.
Performance-enhancing Blended Winglets have been added to our fleet of 737-700s, and all new 737-700 aircraft arrive from Boeing with Blended Winglets installed.
ATA Airlines operates Boeing 737 and 757 jets. Learn more about Southwest Airlines' codeshare with ATA Airlines.