The Volokh Conspiracy has a discussion on the economic system implied in Star Trek. I have always thought that the people who did it did not really think much about the issue, and the discussion in the comments suggests that there are inconsistencies in the descriptions of the underlying economy.
Addendum: According to a post to the e-mail teaching-econ list, at the beginning of the new Star Trek movie the young Spock is answering multiple, rapid-fire questions, and among his answers is, “non-rival and non-exclusive.”
Update: Another discussion here.
Monday assorted links
44 minutes ago