I know I could just remake these playlists by finding the tracks on Spotify, but many are 10 hours or more of music, and I just don't want to spend the time. In doing a bit of reseearch it seemed like there was a useful webtool that did exactly this, but it was discontinued months ago, so I appeal to the hip masses. It also seems like Spotify is getting really close to knowing what songs are on my playlist, it just can't quite take the final step away from "local files".