One more…

In our IM conversation, Greg also pointed out that you can use the URL format suggested by What Do I Know, but fetch it with http:// instead of itms://. Why would you want to do that? Because you get the XML package that the server delivers, and you can pull out individual PlaylistIDs, so you can point even more directly to albums. Like: Why Is There Air? and Revenge, and even To Russell, My Brother, Whom I Slept With. (Links only work with iTunes 4.)