Does anyone know of a player/manager similar in functionality to itunes?

Basically, I have about 30 gig of music - sometimes I just let it play at random any track from the library. What I would like to do is, if I hear a track I like at the time - right click and add it to a playlist, then this is where it gets tricky - I would like to grab all the actual mp3 files from that playlist and transfer them to my phone.

I can add songs to a playlist in rhythmbox, but I cant grab all the mp3 files associated with that playlist.