One of my dreams in the category "technically impossible at the moment" is the idea of having a network of microphones all around the world (in deserts, in the arctic, on a buoy in the middle of the ocean, and so on) which stream their input to the internet in high quality and you can access them all the time (wouldn't that be great?).
Of course this isn't feasible yet (power consumption, maintenance, network uplink, costs ...), but as a first step into that dream, I mounted a very cheap unused microphone outside one of my windows and stream it to my server using an unused laptop.
Maybe that's boring for most people, but I love to listen to it - even if the quality of that system is worse than bad:
http://falsemirror.de:8000/mic.m3u