The Korean online shop PCBee has a small review (in Korean) of a USB HD TV tuner. What we get with that device is REAL HD with a resolution of 1920×1080, you can also get the video back out through a RGB or S-Video cable (which defeats the whole HD story) and it can (of course) be hooked up to your PC through the USB port. There’s a whole software suite that allows you to record HD video. This thing should cost around 70 EUR in Korea.