Oh - I almost forgot I promised a description of the game of Magic: the Gathering.
This was the very first collectible card game (or CCG). It created the concept, which later lead to perhaps more famous games (in some circles) like Pokemon and Yu Gi Oh.
In M:tG, you and your opponent are playing combating wizards. Your deck of cards represents lands from which you can draw magical energy ("mana") and spells which you cast in an attempt to defeat your opponent. Some spells directly do damage to him/her. Some summon up creatures to do your bidding (such as bashing your opponent over the head). Some conjure up mechanical devices, called artifacts, which can assist you in your battle. Some affect the "world" you're playing in, or modify lands, creatures, or artifacts already in play.
You and your opponent take turns placing land into play, casting spells, attacking with creatures...until one of you loses (most typically by losing all "life points" - you start the game with 20 - but there are other ways to lose).
It's a very well thought out game, which is pretty easy to learn the basics of, but possibly difficult to get REALLY good at. There are, believe it or not, tournaments at which large amounts of money can be won. I've even heard of them being televised on like ESPN23 or some such station.
And, once upon a time, I bought every card which came out when it came out, and was a crazy M:tG geek and collected thousands of cards. Now I'm trying to spread them out to the people who will actually put them to use (hopefully) instead of having them sit in a dark cardboard box, fulfilling no purpose.