This study investigates the organization of conversational interaction via push-to-talk mobile radios. Operating like long-range walkie-talkies, the mobile radios mediate a remote state of incipient talk; at the push of a button, speakers can initiate, engage, disengage, and reengage turn-by-turn talk. Eight friends used the mobile radios for one week; 50 of their conversational exchanges were analyzed using conversation analytic methods. The findings describe the contour of their conversational exchanges: how turn-by-turn talk is engaged, sustained, and disengaged. Similar to a continuing state of incipient talk in copresence, opening and closing sequences are rare. Instead, speakers engage turn-by-turn talk by immediately launching the purpose of the call. Speakers disengage turn-by-turn talk by orienting to the relevance of a lapse at sequence completion. Once engaged, the mobile radio system imposes silence between speakers' turns at talk, giving them a resource for managing a remote conversation amid ongoing copresent activities.We are grateful to Mimi and her friends for making it possible to collect this data. We also thank Jim Thornton, Marilyn Whalen, Paul Drew, Bob Moore and Luke Plurkowski for their helpful insights.

Philip Glenn, Laughter in interaction. Cambridge: Cambridge University Press, 2003. Pp. xi, 190, Hb $75.00.

Drawing on extant research in conversation analysis (CA) and other fields, Glenn's entry in the “Studies in Interactional Sociolinguistics” series is both an excellent introduction to CA for those outside the field and an interesting exploration of the social phenomenon of laughter. The first chapter gives a general survey of the research, which has often focused on the physicality of laughter and its relation to humor. Ultimately, however, the chapter suggests a function of laughter beyond expressing amusement: affiliation with co-participants in social interaction. In chap. 2, Glenn provides a helpful outline of CA. He emphasizes CA's focus on participants' perspectives and provides a cogent explanation for CA's meticulous transcription conventions with the example of silences, marked on CA transcripts in tenths of seconds. To leave them out, he argues, would be to assume from the beginning that silences in talk mean nothing (p. 37) – an idea that most competent talkers, let alone CA researchers, would reject out of hand.