Fly-Rights This Department of Transportation Aviation Consumer Protection Division publication, long available in print, is now online. It spells out what the D.O.T. requires airlines to do in cases of overbooking and discusses delayed and cancelled flights, baggage problems, and other consumer issues.
Passengerrights.com is the place to go if you feel you've been victimized by an airline. From the site you can compose a letter airing your grievances and electronically send your complaint to all appropriate parties with one click -- the site has all the e-mail addresses on file. A part of the site teaches you how to complain effectively.
Rules of the Air Terry Tripler, an authority on airline carriage rules, maintains this guide to the check-in time limits, baggage regulations, and other rules observed by more than a dozen U.S. airlines, including how each carrier handles overbooking and denied boarding.
Airport Parking This Web site describes the short- and long-term parking facilities at 90-plus airports, mostly in the United States. For most airports, other info is also accessible, such as ground transportation, the availability of luggage carts, porter service, baggage checkrooms, lockers, and even where to get your shoes shined.
Flight Status checker Enter an airline and flight number, then click to find out the flight's departure time and scheduled arrival time.
Quickaid This site contains information on bus and taxi service for nearly 200 airports around the world, many entries with terminal maps.