There are a few things. ProgDVB and RitzDVB are the ones I have used. They are more for watching TV, but I sucessfully watched the famous DISH 500 channel on my laptop from the main desktop using ProgDVB so if you have a network, you can control the card from, say, the bedroom.
I think ProgDVB is the easiest, but my Athlon 700 just couldn't hold up.