Lots of people seem to be making Spotify playlists of John Peel's Festive 50 charts.
Once I can get the despotify gateway working (it's not accepting the session IDs at the moment), it should be possible to resolve the tracks to Spotify track IDs and create Spotify playlists automatically. Update: I got the Python bindings installed, but it's apparently not possible to get a track's Spotify URI this way, only the relative track number within a playlist or list of search results.
The description of how the despotify authors found the recent security vulnerability in Spotify is interesting:
It turned out that whenever you added someone else's shared playlist, the Spotify client software would request information from Spotify's servers about the author of that playlist. The information returned contained things like a hash (based on a salt and the user's password), date of birth, city and other things that Spotify knew about this user.
We realized that the password hash that was transfered to the client when you added someone else's playlist could be used as a way of authenticating to the server as the owner of the playlist, without knowing his or her password.