Airlines of the World (FlightStats) - Airlines of the World
Airlines of the Web - Conduct a free airline airfare search and book your airline, car rental, and hotel reservations for American, Continental, Delta, Virgin, Singapore, United, USAirways, Southwest, Air Canada, Canadian, and many more airlines in Asia, North America, Europe, Africa, Australia, South America, and the Middle East!
Bureau of Transportation Statistics - Airline Data and Statistics
The Airline Codes Web Site - This web site has been setup to help you cut through the jungle of all those codes and abbreviations used in and around the Airline Industry.
Webport - Your airport on the web
Wikipedia - Wikipedia's list of airlines
Wikipedia - Wikipedia's airline page