Here are some useful links to websites that might be of interest to the radarspotter.
FlightAwareStarted in 2005, the first to offer free flight tracking for private and commercial aircraft. Its free PiAware software is one of the easiest solutions for tracking Mode-S flights using a low cost SDR and RPi combination. And it shows all available MLAT plots unlike others that block some MLAT flights.
Flightradar24.comGreat site to track aircraft on a map, including previous 16 days, and excellent
Aviation Database to look up aircraft by hex code, registration and airline.
PlanePlotterLow cost extension for all Mode-S receivers. Share data and plot the location of non-positional aircraft using multilateration (Mlat).
Gatwick Aviation SocietyAnother great extension for Basestation. Convert Mode-S hex codes into an aircraft type and registration using the online form or download Active Display.
Military Airshows in the UKList of military airshows in the UK
Virtual Radar ServerDisplay your SBS data on a Google map in a browser window. Great for viewing your local aircraft when you’re away from home.
AirframesLookup a Mode-S hex code and find out to which aircraft it belongs.
The Aviation HeraldGood resource for reported incidents and crashes.
Airliners.netFantastic site for aircraft photographs.
LibhomeradarUseful database of reported Mode-S contacts and searchable database.
Skyliner.netAviation news and latest aircraft deliveries.
FlightglobalAviation news.