RTL-SDR is a cheap software defined radio that uses a DVB-T TV tuner dongle based on the RTL2832U chipset and R820T2 tuner.
RTL-SDR Blog R820T2 RTL2832U 1PPM TCXO SMA Software Defined Radio
RTL-SDR, DVB-T USB Stick for SDR Reception
100KHz-1.7GHz RTL-SDR USB Tuner Receiver DIY Kit Sells for $33
RTL-SDR - Hacker Warehouse
Buy DYTesa USB2.0 FM DAB DVB-T RTL2832U R820T2 RTL-SDR
RTL-SDR: The COOLEST USB Dongle (Software Defined Radio)
GetUSCart- Nooelec NESDR Mini 2+ 0.5PPM TCXO RTL-SDR & ADS-B USB
RTL-SDR dongle prototype with the relevant integrated components