FlightAware was easy to setup and great fun to use. Can track flights flying over your head leaving contrails spoiling your beautiful blue sky. Get the story about a plane and its current flight. Sharing your data with FlightAware gives you free access to their Enterprise plan, well worth it.
Basically you setup a Raspberry Pi, with a ADS receiver which monitors the airwaves for ADS data from flights within range. The area I live in is rather hilly, so at first I wasn’t happy with the units range so I added an external antenna which dramatically increased my systems range. All and all the system cost about $150. You leave it running, then can remotely monitor you PiAware unit over your network through a browser. Plus you can access your data directly from FlightAware’s site, well your data anyway.
You can overlay current weather. You can also spend more for better antennas and higher antenna mounting, which would improve you stations reception.
All and all, great fun, nice use of a Raspberry Pi.