Almost 25 years after the death of Marshall McLuhan, the Canadian writer who coined the term "global village" and philosophized about the impact that television had on our minds and bodies, some of his theories are taking on a larger meaning.

His most enduring idea was the concept of "hot" and "cool" media.

A hot medium is one that is "low in participation," while the cool one is high in participation, "or completion by the audience." Therefore the radio is a hot medium and the telephone is a cool one. The movies are hot, TV cool. McLuhan published this theory in 1964, and in the years since then the media have become so pervasive and interconnected that the idea of "participation" would seem to require redefinition. Broadcast TV may have been "cool" in the 1960s, but compared to cable TV and the Internet, it seems hotter than hell.