You can listen to all communications between a control tower and it's incoming airplanes or even track an airplane from the beginning of it's flight to it's arrival.
By live feed from a satellite you will know the planes current altitude and speed, where it is located and a glimpse at the approximate time of arrival. The mapping of flights in real-time is based on the air traffic control system.
There are no costs or restrictions in doing so and many official websites are starting to provide the service. This can come in useful when curious about a family members flight, or when anticipating an arrival without knowing of it's progress.
Air traffic control (ATC) is responsible for providing crucial information to pilots around busy airports. They communicate with pilots on designated radio frequencies to keep airport operations running smoothly and safely.
While every airport varies, terminal controllers usually handle traffic in a 30 to 50 nautical mile (56 to 93 km) radius from the airport.
Using the Internet you can also listen in live to aircraft radio chat between planes and the control tower, and plane to plane traffic.
Hear what happens behind the scenes at some of the world's busiest airports. Listen to live transmissions between air traffic controllers in the airport tower and pilots landing and departing from the airport.
Call signs in aviation are derived from several different policies, depending on the type of flight operation being conducted, and depending on whether the caller is an aircraft or a ground facility. In most countries, unscheduled general aviation flights identify themselves using the call sign corresponding to the aircraft's registration number (also called N-number in the US, or tail number).
Click this link to listen to live aircraft radio traffic: http://www.liveatc.net.