I wanted a DVB‑T USB stick (which I will probably want to plug in DSM‑G600  and have network TV in later phase) with ability to receive both analog and DVB‑T signal, so I bought Hauppauge HVR 900  while my UK visit.
$ lsusb | grep Hauppauge
Bus 005 Device 004: ID 2040:6502 Hauppauge

Alternative approach from mailing list  modified to work out‑of‑the‑box on recent Debian box:
Insall kernel source and symlink source directory which drivers need:
sudo ln -s /usr/src/linux /lib/modules/`uname -r`/source

Checkout source of userspace tuner and compile it
hg clone http://mcentral.de/hg/~mrec/userspace-tuner/
cd userspace-tuner
sudo ./build.sh
cd ..
hg clone http://mcentral.de/hg/~mrec/em28xx-userspace2/
cd em28xx-userspace2
make
modprobe em28xx.ko // this will load the videodev modules
rmmod em28xx.ko
insmod em28xx.ko

This instructions still doesn't work
                                                  
Following older instructions are slight modification of blog post in German  which I used with a bit of Google translate  to make it work on Debian unstable. I will assume that you already have kernel source and build tools, because you are running unstable :‑)
• dmesg output after plugging in the card: Hauppage_WinTV_HVR_Rev._1.2.dmesg 
• upstream driver 
This instructions are based on spanish ones  with updated urls
Fetch drivers
mkdir hvr900
cd hvr900/
wget 'http://supportde.terratec.net/modules.php?op=modload&name=Downloads&file=index&req=getit&lid=1049'
unzip Cinergy_T_USB_XE_Drv_Vista_XP_6.11.23.01.exe
cp Cinergy\ T\ USB\ XE/BDA\ Driver\ 6.11.23.01/Windows\ Vista\ \(32Bit\)/AF05BDA.sys .

Install development tools
sudo apt-get install mercurial make gcc libc6-dev kaffeine

Checkout latest source
hg clone http://mcentral.de/hg/~mrec/v4l-dvb-experimental

Extract firmware
cd v4l_experimental/xc3028/
gcc -o convert convert.c