  The style of mathematical models known to probabilists as Interacting
Particle Systems and exemplified by the Voter, Exclusion and Contact processes
have found use in many academic disciplines. In many such disciplines the
underlying conceptual picture is of a social network, where individuals meet
pairwise and update their "state" (opinion, activity etc) in a way depending on
the two previous states. This picture motivates a precise general setup we call
Finite Markov Information Exchange (FMIE) processes. We briefly describe a few
less familiar models (Averaging, Compulsive Gambler, Deference, Fashionista)
suggested by the social network picture, as well as a few familiar ones.
