Get an RTL-SDR stick. There is such a community around this hardware that you can be up and running in a few minutes after it arrives. I purchased a "RTL-SDR B

Get an RTL-SDR stick. There is such a community around this hardware that you can be up and running in a few minutes after it arrives. I purchased a "RTL-SDR Blog R820T2 RTL2832U" a month ago. It has an upgraded oscillator (less setup hassle) and comes with a usable antenna. In the Bay Area I've been able to listen to FM radio, NOAA weather, SJC Airport tower, Police - both NFM and digital, and ADS-B. I'm quite happy with the purchase, and excited about the possibilities of what I can do next.