10. The machine system of claim 8 wherein said contemporaneousness of substantially same topics of focus or of interest in the minds of the topically contemporaneous strangers and in the mind of the first user occurs in an immediately preceding and predetermined time period that is chronologically adjacent to when a corresponding invitation is presented to the first user.
8. The machine system of claim 1 wherein: the first presentations include automatically presented invitations to information exchange forums which forums include or have further invited thereto, one or more persons who are topically contemporaneous strangers to the first user, where such topically contemporaneous strangers are persons not known to the first user to contemporaneously have substantially same topics of focus or of interest in their minds as a relatively current topic of focus or of interest that the first user is determined by the machine system to more likely than not have in mind, and the one or more topically contemporaneous strangers are predetermined by the machine system to contemporaneously and more likely than not have substantially same topics of focus or of interest in their minds as the relatively current topic of focus or of interest that the first user is predetermined by the machine system to likely have in his or her mind; wherein said likely topics of focus or of interest are determined by the machine system based on specific sub-portions of respective firstly presented content that the first user and the one or more persons respectively centered their attention upon.