Newspapers may be constrained in their ability to charge for content by U.S. antitrust law. Yet two columnists in the Wall Street Journal use the music industry as a template for the possibility that newspapers could work together to charge for content. The model would essentially involve newspapers charging sites for the reproduction of their content, just as songwriters make money from the playing of their songs on the radio or at nightclubs. To be successful, the newspapers would need an intermediary to monitor the online replication of their articles, and thereby legally ensure payment for their content.
You can read the Wall Street Journal column on their website here.