In one of the major Dick Tracy arcs of the 40s, Pruneface maybe, there's a storyline revolving around saboteurs who exchange information throught he operator jukeboxes.  You put a nickel in and get to request the music from an operator/DJ somewhere.  I'm not sure what the advantage was supposed to be or if they used phone lines or what.  It seems pretty expensive and complicated.

Chris Herzog

"The Devil's on the loose and he's dancin' with the Mummy!!!"