DVB-T dongles based on the Realtek RTL2832U can be used as a cheap SDR
(software defined radio), since the chip allows transferring the raw I/Q
samples to the host, which is officially used for DAB/DAB+/FM demodulation.

RTL-SDR provides some tools to work with these devices:

rtl_eeprom:	EEPROM programming tool
rtl_fm:		general purpose analogue demodulator
		(narrow band FM, wide band FM, AM and SSB)
rtl_sdr:	tunes the device and captures raw data to a file
rtl_test:	check the possible tuning range

Asynchronous mode is NOT currently supported on OpenBSD; some programs
have been modified to force synchronous mode, the following are not yet
available:

rtl_adsb:	simple ADS-B decoder (aircraft tracking)
rtl_tcp:	provides a network server for remote access to an SDR
