Finding truth in pop culture

One of the things that I've struggled with for some time is where should the line be drawn for what Christians partake of in popular culture. Some people, for instance, won't watch a movie if it's rated more than PG while others have no problem watching an R rated film. Some will only listen to music they can find at the Christian book store or on Christian radio, while others have no problem listening to Rage Against the Machine or other such acts. I've heard lots of theories for why we should or should not take part in popular culture. If you've been around this blog for long you know that I tend to fall on the more liberal side of the argument, though I can totally understand the conservative perspective. Well, I finally found an article that breaks down the whole concept quite well and will help to direct my thinking on this subject for some time to come. (Note: the article is fairly long)