About.com
Post 9/11, a number of US airlines have started to publish information about estimated security wait times for passengers. Click here to find out more.
http://businesstravel.about.com/library/weekly/aa010102a.htm

Air Text
Live flight information direct to your mobile phone.
http://www.airtext.co.uk/

Air Traffic Control System Command Center
Real-time information about weather related delays at major US airports.
http://www.fly.faa.gov/flyFAA/index.html

Airline Destinations.co.uk
Use the flight map on this website to check which airlines fly to which destinations from which UK airport.
http://airlinedestinations.co.uk/

Airline Route Maps.com
Airline route maps arranged by country or carrier.
http://www.airlineroutemaps.com/

Airline Timetable Images
Just as it says.
http://www.timetableimages.com/

Airwise.com
Search for arrival information about a particular US flight.
http://travel.airwise.com/arrivals/index.html

Airwise.com
Worldwide flight schedules at the click of a mouse.
http://travel.airwise.com/schedules/index.html

American Express
Based on radar data, the Flight Tracker generates online views of the status of current flights. Track a flight by airline name and flight number, or by city and arrival/departure times. Unfortunately, the facility only covers flights to or within North America.
http://209.113.170.222/amex/flight_tracker/ft_main.asp

BAA
Click on the "flight timetable" link on the main page to view the schedules for flights to and from BAA's UK airports.
http://www.baa.co.uk/

BAA
Live flight arrivals at major UK airports.
http://www.baa.co.uk/main/general/baa/flight_arrivals_frame.html

BAA - Flying Messenger
Use the Flying Messenger service to check the status of any scheduled flight arriving or departing from Heathrow or Gatwick airport using your mobile phone.
http://www.baa.com/mobile/

BCD Travel
Offers an SMS flight alert service that covers a large number of carriers flying to/from Europe.
http://smsflightalert.bcdtravel.com/

Bureau of Transport Statistics
A mass of airline statistics, including a survey of which US airlines rate best for punctuality.
http://www.bts.gov/oai/

Bureau of Transport Statistics
Use this page to find information on flight delays, cancellations and diversions for America's major airlines and the airports they serve since 1997.
http://www.bts.gov/ntda/oai/index.shtml

Cheap Tickets
A glossary of flight tracking terms.
http://www.cheaptickets.com/trs/cheaptickets/flighttracker/flight_tracker_terms.xsl

Dohop.com
Find the fastest route to your destination by using this online tool to search over 600 airlines around the world for the best flights and connections.
http://www.dohop.com/

Executive Travel Skyguide
Find out which carriers are travelling your route and at what time with the aid of this international flight search tool.
http://www.skyguideonline.com/search/

FBOweb.com
A commercial site that puts a range of flight tracking tools at subscribers' fingertips.
http://www.fboweb.com/

Federal Aviation Administration
Provides real-time information about flight delays at US airports.
http://www.fly.faa.gov/

Flight Arrivals.com
Check for delays at airports or to arriving or departing flights at airports all over the US and Canada, as well as a few overseas.
http://www.flightarrivals.com/

Flight Aware
North American real-time flight tracking and information tool.
http://flightaware.com/

Flight Explorer
Global flight tracking software.
http://fasttrack.flightexplorer.com/

Flight Mapping
An interactive map showing airline network routes from the UK to destinations worldwide. Find out which airline flies to where from the UK.
http://www.flightmapping.com/

Flight on Time.info
Punctuality data for charter, scheduled and low-cost airlines operating from London airports to destinations worldwide.
http://www.flightontime.info/

Flight Wait
A Google Maps mashup that displays real-time flight conditions and delays in US airspace.
http://flightwait.com/

Flightlookup.com
Search for a flight in four easy steps.
http://www.flightlookup.com/index.html

FlightStats
A customizable website that allows you to pull-up detailed information on the status of a flight, including a flight events timeline that shows you what changes have been made to the shedule.
http://www.flightstats.com/

FlightView
Online flight tracking solutions.
http://www.flightview.com/

FlyteComm
Track the status of any flight arriving or departing the United States or Canada.
http://www.trackaflight.com/
http://www.flytecomm.com/cgi-bin/trackflight
http://www.4airlines.com/trax/flight-tracker.asp

FlyteSource-Mobile
Receive flight arrival alerts and flight information on your cell phone.
http://www.flytecomm.com/

Jetnav.co.uk
Discover which carriers fly to your chosen destination from airports all over the UK.
http://www.jetnav.co.uk/
http://jetnav.blogspot.com/

Low Cost Airline Guide
Search the route network of every known budget or no frills carrier in Europe.
http://www.low-cost-airline-guide.com/

OAG
A huge list of flight schedules from around the world, along with flight updates.
http://www.oag.com/web/default.asp
http://www.oagflights.com/

Scanning Reference
Lists prohibited electronic items on major American carriers.
http://www.panix.com/~clay/scanning/rules/airlines.html

Smarter Living
Smarter Living's flight search engine lets you find all scheduled flights in the United States.
http://www.smarterliving.com/air/schedules/?source=
jj&value=flightsearch&ctid=jjflightsearch

South African Airways
Arrivals and departures information and delay notification of SAA flights.
http://www.flysaa.com/flight_status/flight_status/flight_status_frameset.html

Star Alliance - Star Alerts
Receive text alerts on your mobile phone or device about major changes to the scheduled departure/arrival time of any Star Alliance flight.
http://www.staralerts.oag.com/

The Office of Airline Information
Find out which American airlines are the most punctual.
http://www.bts.gov/cgi-bin/oai/ontime_js.pl

Transport Direct.info
An official public transport information website that contains a flight finding tool.
http://www.transportdirect.info/
http://www.transportdirect.com/

Trip Advice
Track domestic flights in the USA.
http://www.tripadvice.com/webtrax/query.htm

TripIt
A free personal travel assistant: email TripIt your travel plans (flights, hotels, cars, trains, cruises, etc) and they will generate a master itinerary for you that will include information about weather, maps, directions restaurants and sightseeing relevant to your destination.
http://www.tripit.com/