I have a lifeview flyvideo3000, cost 47€ and works like a champ

You can get them pretty easily, if its anything but hauppage you'll have stereo sound and radio as well. (hauppage cards cost alot, and the cheapest models are monotv, no radio or anything).
The software comes with the card.
If you happen to have a vivo card, you can get software to view the videoinput port from the card manuf site. Eg. asus has asus live to watch input video.
-M