Very nice writeup! Getting into SDR is an eye opening experience. A little stub of conducting wire lets you tap into a dimension that is completely invisible to our senses. It's almost like hearing there are billions of neutrinos passing through your thumbnail every second, except there are people and machines on the other end.
There's a huge list of things you can do with the RTL-based SDRs in the article. Expanding to more capable hardware generally improves the quality of the data and enables higher bandwidth use cases that are difficult to pull off with cheaper radios, but for $30 you can get into all sorts of interesting stuff. (Turns out making your own antennas is half the fun)
If you want to just poke about you can access SDRs online through web-based consoles like websdr.org and kiwisdr.com (mostly shortwave and ham bands, the latter has a cool trilateration feature) or some of the major SDR software products (like SDR-Console and SDRSharp) have their own volunteer network of radios you can tune into (with caveats and limits of course) with their software.
There's a huge list of things you can do with the RTL-based SDRs in the article. Expanding to more capable hardware generally improves the quality of the data and enables higher bandwidth use cases that are difficult to pull off with cheaper radios, but for $30 you can get into all sorts of interesting stuff. (Turns out making your own antennas is half the fun)
If you want to just poke about you can access SDRs online through web-based consoles like websdr.org and kiwisdr.com (mostly shortwave and ham bands, the latter has a cool trilateration feature) or some of the major SDR software products (like SDR-Console and SDRSharp) have their own volunteer network of radios you can tune into (with caveats and limits of course) with their software.