This seems like an easy one but it would be very useful I think. I am often listening to a long list of shuffled songs and I hear one I'd like to add it to another playlist (e.g. fast driving music). As it is now i have to go to "file info" copy the file path, go find my "fast driving music" playlist m3u file, open it with notepad, and paste filepath in there.
What I would like to do is right click on a song and click "add to playlist" on the context menu. This would slide out a secondary menu with the last few playlists I have "added" songs to (using this method) as well as the options to "browse" for a list or "create" (which would of course then bring up the open or Save As windows dialogs).
If you wanted to expand on this idea you could add a "move to playlist" option as well that reuses the ui components that the Add uses.
Thank you for listening to me!