Roger Ebert has posted a pretty good article about his relationship with the concepts of McLuhan, HERE
One that I find myself butting up against quite a bit is the concept of the rear view mirror. It is impossible to always see where technology and culture are headed. When I was co-hosting a podcast about new media, called Media Sound Off, I wanted the premise of the show to consist of longform interviews with people pushing the boundaries of media. The majority of the interviews ended up being rather dull and uninspiring. The people on the edge of media, pushing the boundaries don't really realize what they are doing,they certainly don't know how. They are just doing.