Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
I would also be interested in this....I think that it entails stuff like ICE-Cast and SHOUT-Cast
 
or Quicktime Broadcaster, which is free from Apple. if you're wondering how to get listed in the Radio part of iTunes i wouldn't count on it. after 3 years of trying to figure it out it's still a mystery who is in control of that. someone at Apple. but you can def broadcast from QTB, ShoutCast, Live365, etc.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.