I'd like to throw my hat in the ring and give an overview+demo of GNURadio, a FOSS package for graphically developing DSP applications and interfacing with Software-Defined Radios (SDR). I spent last summer at MITRE using this software heavily, and I'm also using it for my MQP work. For the demo, I'd like to bring down some hardware from my lab (https://www.ettus.com/product/details/UN210-KIT) as well as the $20 RTL-SDR dongle (http://www.nooelec.com/store/sdr/sdr-receivers/nesdr-mini-rtl2832-r820t.html) to show reception of broadcast FM, ADS-B telemetry from airplanes, as well as some real time views of Wi-Fi, Bluetooth, and streaming drone footage from a DJI Phantom 3 Pro. 

Here's the outline:

What's SDR?

Why should we care?

Why do I care?

Who uses GNURadio?

GNURadio fundamentals

    Introducing the workflow/flowgraph interface

    Cloning/Building/Installing (this won't be specific, just mentioning the GitHub repo and where the quickstart guide is)

    How to contribute (also GR-hackfest!)

    GNURadio as a software development framework

        Ex: GQRX (http://gqrx.dk)

For the demo, I'll show off some stuff I've made with GNURadio, as well as GQRX to interface with the RTL-SDR. I'm pretty confident that I can cram it inside of 2 hours, because I'll be basically recycling the slides I made for my MITRE presentation, minus the branding and project-specific content.