1. A method comprising: analyzing first data corresponding to imagery captured by a user's smartphone camera, to obtain identification data corresponding to a first physical object depicted in the imagery; issuing instructions that a social network graph data structure be updated to add node and tie elements, the node element corresponding to the first physical object, and the tie element indicating interaction by the user with said first physical object, information in said social network graph data structure being published by a service for viewing by one or more third parties; wherein the first physical object is identified by reference to the first data, and the user's interaction with the first physical object is automatically publicized to said one or more third parties.