I've just started playing the Witcher. After a romantic encounter with Triss during the tutorial, I received a "card" showing a picture of her. Now when I view her entry in my journal, there is a heart and an option to "view card". I'm guessing other characters have cards as well. Are there multiple cards per character? Are they all related to getting said character into bed, a rather twisted adult game of "gotta catch em all"? And is there any point to collecting said cards other than to ogle them?
Yes, you get one of those cards for every woman you get into bed. Generally there is only one card per character, but there are two characters that have two cards each. Collecting all of them does not do anything besides letting you see them, there is no additional benefit.
These cards are probably the most-criticized aspect of The Witcher. You can try to get them all, but you can also completely ignore that part of the game. They don't have any further effect on the game.