Does anyone have any Air Courier stories?

I'm interested in taking advantage of some of the air courier deals. I'm taking a trip to New York from Los Angeles in mid december. Does anybody have any tales to tell? How does customs/checking in/checking out go? How often do you personally travel as an air courier? How did you find your first couriering job? Do you do it as a career, or just for casual travel? I'm sure it's a pretty reliable way to get to and forth around the world, would you recommend it to others? I've visited several websites and read a few books from the library. Most of the sites recommend joining an ociation or getting a broker. They all require fees, I just wanted to hear others stories about it before I went ahead with it. Thanks alot.