I found an article that was a good 5 years old, but it helped me setup my internet radio streaming! I decided to post these instructions on a few of the forum search results that popped up when I was looking for answers myself.
I have an Apple TV2 and two AirPort Extreme devices. I wanted to stream music throughout the house and this works great. I love listening to NPR, but couldn't find the local stream in the "Radios" section of iTunes. I found this article and it mentioned how to (1) open streams within iTunes and (2) add those streams to a playlist. Doing this was the perfect solution!
(1) Find the stream you'd like. For NPR, I went to the Station Finder (NPR: Station Finder
), clicked on my station, found their "Listen Live" link and managed to find the stream (in my case: http://witf.ic.llnwd.net/stream/witf_mp3.pls
(2) In iTunes, click "Advanced" then "Open Stream" and paste the link into the box that comes up and hit Ok.
(3) Your stream will start playing. You now need to find the stream within your iTunes library. Click "Music" in your iTunes left menu. (It'll be in there).
NOTE: If you're having trouble finding it, right click on the sortable columns at the top (Name, Kind, Artist, etc) and make sure 'Date Added' is checked. Then sort by 'Date Added' by clicking it. Your station will be at the top (or bottom) of the sorted list.
(4) Create a new Playlist (File/New Playlist). Name it whatever is good for you. I named mine "NPR".
(5) Drag the stream from the "Music" folder into the Playlist.
Now, when you use your Remote app, you can see the playlist and simply start it playing. You can then use the Remote app to pick which AirPlay devices to stream to.
Note: This will cause your stream to be a "Song" in your library, so if you like to just put your library on random and let it go, you may have problems (i.e. your NPR stream will start playing while you're trying to listen to music). I tried removing the "Song" from the music list, but it then removed it from the playlist.