I am admin for a student newspaper that is running WordPress as a CMS. We did not want to create a user account for every freelancer that contributed a story, but we wanted to be able to show their name in the byline.
I found this blog http://www.wprecipes.com/rewrite-author-name-with-custom-field
that talks about using the custom field to rewrite the author's name.
This works as well, to overwrite the default display name and add the specific author to each post.
I created one account for all freelancers and added a custom field for guest-author.