So thats Balint, he works for a company called Ettus Research.
Here is a pic of me and him from the last Defcon in Las Vegas (so you can tell I know what I am talking about).
You asked if anyone had experience with SDR dongles:
This is my personal collection of publicly available SDRs. Starting from the top left going clockwise that is a HackRF, a Ettus B210, a Nuand bladeRF, a E4000 based tuner, a Nooelec TCXO R820t, a Funcube pro, a Ubertooth, a Nooelec R820t2. The Dongle at the bottom is a hybrid E4000/RTL2832 with the new antennas they ship with.
Depending on what you want to do the RTLs are great for amateur/backup use. I normally carry a few around with me where ever I go, the packaging looks like this:
This particular dongle runs $25. Cheap enough to throw away or leave behind if need be.
If you have any questions about how they are useful, the differences between models, or how to get started with them I am happy to help.
One quick example of what they can be used for is creating a heatmap over time. Using the free tools
rtl-power you can create a map of the visible spectrum in the devices range that looks something like this (a 24 hour example):
If you combine the rtl with a low priced platform like a beaglebone or raspberry pi you can build an effective spectrum monitoring tool for less than $100. At that point there are a ton of fun things you can do like attach a battery, add a cellular modem and mail the package to someone.
Sorry for the long, photo heavy response.
