Yeah, i've got a Pinnacle PCTV card that does that :mellow:
Basically the card has a TV aerial port on the back and also a composite port, and an S-Video. You plug in the aerial to the aerial one (duh!) and you can watch TV in a window, or go full screen :ermm: Tis good. As my I have a TV plugged into the TV out I can watch TV on the TV or one of my flat screens woo :(
The composite in lets you plug in a VCR or Playstation if you like too :- Oh and the cards got an audio out that you plug into the line-in on your sound card so you get sounds from the TV input woo :P