I've a notion to track down every public .ogg radio stream that I can.

This list is pretty big and I'd really like to attatch notes like, genre, location, homepage because oftentimes the data attatched to the stream is very minimal or nonexistant.

How can I label internet streams I've saved in playlists?

You can't. People tend to display information by tagz code.
Just to show what I mean:
$if($stricmp(%path%,stationXYZ),'Information: I am station XYZ',)