Here's another trick a $10 Software Defined Radio dongle can do on Android. You plug in the dongle, and kick off ADSB Receiver, a free Android App. And in a few moments, you'll see something like this:
That's live flight data. But the thing, that's not being pulled off the web. That's being received directly from the airplanes themselves (at least, as I understand it). The whole thing is powered by ADS-B, a standard by which planes broadcast their location data.
I won't claim to understand the arrangement, but I'm still amazed that I can pick up this data using little more than a $10 dongle and smart phone. There's no encryption used in the system, which I find surprising (though like most older protocols, that's not really shocking).
Is this actually useful? Sort of. One of our favorite parks, Gravelley Point, is directly adjacent to National Airport. It's the perfect place to sit back and watch the miracle of flight, as planes take off and land just overhead. Hitting the park with this app open, and also using the radio to listen to Air Traffic Control would be pretty sweet.
I also like the idea of discovering an open protocol that's all around us, yet invisible to most.
Makes me wonder what other data I can pick up with my little receiver...