About The RTL-SDR Dongle
For something that only costs $25 that can receive radio, weather, police and other radio freqencies is pretty amazing. The best part there is no interenet required so it works great when traveling off the grid or wanting some cheap entertainment in remote locations.RTL-SDR is a very cheap ~$25 USB dongle that can be used as a computer based radio scanner for receiving live radio signals in your area (no internet required). Depending on the particular model it could receive frequencies from 500 kHz up to 1.75 GHz. Most software for the RTL-SDR is also community developed, and provided free of charge.
The origins of RTL-SDR stem from mass produced DVB-T TV tuner dongles that were based on the RTL2832U chipset. With the combined efforts of Antti Palosaari, Eric Fry and Osmocom (in particular Steve Markgraf) it was found that the raw I/Q data on the RTL2832U chipset could be accessed directly, which allowed the DVB-T TV tuner to be converted into a wideband software defined radio via a custom software driver
Where to Buy the RTL-SDR Dongle
eBay has a nice selection of these USB radio receiver dongles. You can get it without an antenna, or pay a little more for a complete kit which comes with an anenna. Because these devices use open sourced software, you are not paying $100 or more. These would make a great stocking stuffer or gift this holiday for your techie friends that are stuck indoors.
Quick Start Guide
If you need help setting up the software or learning how to use your RTL-SDR Dongle, check out their Quick Start Guide