This essay traces ideas about a fundamental aspect of human interaction, participation, from an initial conception of the “speech circuit” through mid-century notions of “channel” and “phatic communion” to Goffman's innovative rethinking of the issue in terms of “mutual monitoring possibilities” and his trail-blazing analysis in the late essay “Footing”. It concludes with a discussion of current research in conversation analysis, linguistic anthropology and pragmatics that investigates the complex structures and practices of participation that characterize human social interaction.