Since RTLSDR became a consumer grade RX device, numerous talks and open source tools enabled the community to monitor airplanes, ships, and cars... but come on, what we really want to track are cell phones. If you know how to run cmake and have $50 to pick up an RTLSDR-E4000, I'll make sure you walk out of here with the power to monitor LTE devices around you on a slick Kibana4 dashboard. You'll also get a primer on geolocating the devices if you've got a second E4000 and some basic soldering skills.