If you are running an inexpensive Raspberry Pi ADS-B receiver with dump1090 then you can install the PiAware Package from FlightAware to freely view nearby flight traffic and transmit this data to FlightAware’s tracking network. Most aircraft within Europe by 2017 and USA by 2020 will be required to have ADS-B transmitters onboard.
FlightAware’s user-hosted worldwide ADS-B receiver network tracks about 90,000 unique aircraft per day and feeds this live data into the FlightAware website in combination with other public/private flight tracking data sources. FlightAware has over 500 user-hosted ADS-B sites online across 60 countries, with top contributors tracking over 10,000 aircraft per day. To see how ADS-B data is put to use, check out the FlightAware Live Map.
The PiAware installation process takes only a few minutes. If you don't have PlanePlotter, you can download it and then send FlightAware your installation's serial number and we'll buy you a license. FlightAware will also give users a free Enterprise Account ($90/month value) in return for installing PiAware.