When I was a little kid (around '80), I once got to fly in the cockpit with my dad, then an airline pilot. He had me speak over the radio to Chicago as we approached. He told me exactly what to say, it was just something like the flight # and whatnot. He did it as a joke for the traffic controllers, for them to hear a little boy's voice on the other end.
It was a good joke and a thrill for me, and no harm done. Of course that was a different time for airlines (flying in the cockpit?!).