Going through some old notes, I found some other references to both Marc Smith and Joshua Tyler. Marc wrote about Netscan in, “Tools for Navigating Large Social Cyberspaces” (Communications of the ACM, April 2002, pp51-55). Joshua has a paper from when he was at Stanford entitled, “When Will You Read And Reply to My Email? A Study of Rhythms and Temporal Patterns in Email Use.”    (8Z)