NYU economics professor Nicholas Economides describes the Internet (35 years old in September) in terms of the industries it’s displacing. The U. S. Postal Service is becoming obsolete. In the last five years, more than one out of every 10 radio listeners between the ages of 25 and 34 have stopped listening (Clear Channel, Citadel and Cumulus Media have seen share prices drop 23%, 40% and 26% respectively in the last year). Newspapers have watched revenue from help-wanted ads plummet by more than $3.7 billion in the last five years. And telephone service is almost certain to see some big heavy changes.