Innis I found insightful for his view of how technology changes cultures because the dominant means of communication changes what it means to be human.
So, we're still a century or so away from this with regard to smart phones etc. TV barely reached this point before it went into decline (http://www.nytimes.com/2011/05/03/business/media/03televisio...). Newspapers did, quite likely, as did radio.
So long as people complain about how devices are changing us, they are not invisible, so anyone engaged in critical commentary (at least in the popular press) is proof that we are nowhere near this boundary.
Wearables may change the timeline for ubiquitous computing, but again: so long as there is hand-wringing about how the technology is changing us, this transformation is not complete.
At no period in human culture have men understood the
psychic mechanisms involved in invention and technology.
Today it is the instant speed of electric information
that, for the first time, permits easy recognition of the
patterns and the formal contours of change and
development. The entire world, past and present, now
reveals itself to us like a growing plant in an enormously
accelerated movie. Electric speed is synonymous with light
and with the understanding of causes.
— Marshal McLuhan, Understanding Media: The Extensions of Man (1964)http://www.marshallmcluhan.com/common-questions/
Now there are four possible readings for the last word of the title, all of them accurate: “Message” and “Mess Age,” “Massage” and “Mass Age.”
McLuhan's Understanding Media: The Extensions of Man is one of them.