Hedda Hopper and Louella Parsons both appeared as themselves in a few
films. You might even make a case that they had more power to make or
break films (or at least careers) than any similar "journalist" today.
There also seems to be a fairly common tendency to use local reporters
in films set in a particular city. "Volcano" is the most recent
example i can think of; most of these seem to be almost large-scale
Screen-L is sponsored by the Telecommunication & Film Dept., the
University of Alabama.