Southwest currently operates 544 Boeing 737 jets (as of September 30, 2009).
http://www.southwest.com/about_swa/press/factsheet.html#Fleet
548 (as of December 31, 2010) this number will soon change because Southwest is merging with Airtran another large operator of 737 aircraft.
Southwest Airlines currently only operate Boeing 737 airplanes. There are several different versions of this airplane though, so the seat count can vary.
There are many airlines that primarily use Boeing 757 planes. These airlines include Delta Airlines, United Airlines, American Airlines and UPS Airlines.
Typically Boeing 737s have a 2 class seating arrangement but they may sometimes also have a 1 class seating arrangement. It depends on the airline.
The Boeing 787 can accommodate for 223 passengers. The Boeing 787 is used by many airlines including All Nippon Airways, Japan Airlines, United Airlines and Air India.
More than 34,000 employees work for Southwest Airlines.
Boeing Airlines, Inc is the name of the company that manufactures many of the planes that fly today.
United Airlines currently has 24 Boeing 747-400 in service.
None
The only subsidiarity Southwest has is AirTran Airways.
2
No they support many different airlines and the owners are based in Southlake, Texas.
There are many of airline nation wide. The name of some airlines are American Airlines, Southwest, Orbitz and United airlines.