Halo Theater

I really love the whole idea of being able to go back and watch games.  I am having fun with it.  I like going back and watching funny (stupid) things I did during games.  I like taking pictures and saving them.  Its nice to be able to go back and watch the good players to see how they play.  I am having as much fun with it as I am playing.  Wonder why other games don't have this option. 

So explain to me what I would have to get to save these games to my computer so that I can goof around and make these videos like I have seen many of you make.  I have a basic laptop and video editing software.  What do I need to purchase to do this?