Drag this link to your bookmark bar. Click the bookmark on sites with song lists and it will launch them in Spotify.
Songs will be searched one at a time, and the playlist will launch when all searches are complete.
Blue outlines mean still searching, green ones mean the song was found, and red ones mean the song was not found.
This currently works on BBC Radio 6 and WMBR playlists, but can be extended to any listings with a regular format.