A USB DVB-T stick. Included in the package is an infrared remote and a tiny little aerial.
It works on Debian Squeeze (kernel 2.6.32) and Ubuntu 12.04 (3.2; though see launchpad bug 1015836 -- unplugging the stick may cause a kernel oops).
It uses sms1xxx-hcw-55xxx-dvbt-02.fw firmware, which comes in linux-firmware-nonfree in Ubuntu.
The USB id is 2040:c000.