This is great, McLuhan has a lot to teach.

I tend to find his work much more insightful and broadly applicable than Kevin Kelly, et al.

His ideas reproduced in _The Medium is the Massage_ are the most popular, but my favorite is the concept of the media tetrad because it tends towards the descriptive, instead of the prescriptive: http://en.wikipedia.org/wiki/Tetrad_of_media_effects

Taking Twitter for example, instead of saying "Twitter has foo effect on society", McLuhan's tetrad provides a framework for discussion and analysis. e.g., Perhaps you think Twitter retrieves the telegraph, maybe you don't, but McLuhan provides an easy method for discussion.