Use or import YouTube account's Liked Playlist as a Playlist.

[psi4j]

I don't know if this is a simple thing to do or not, but It would be awesome to be able to pull in your YouTube account's liked songs as a playlist. YouTube lets you select your liked songs list and cue it to play next. I don't know if their API lets you do this, but if it does, it would be an awesome feature to have. That's a game changer right there.