Ubiquitous, decentralised, personal, automatic, unmechanical, crossing every social boundary, needing no special skills, responsive to the subtlest tones of voice or intonation, the first machine, I'd say, to be as machines could be, can be, once we transcend the mechanical, the imposed order of written word, of plan, of expert, repetition, wheel ...
centralised control
The first opportunity to relate, in millions, in billions, not as enemies but as friends or equals.