Messages on the answering machine represent a quite unusual form of radio phone-ins. It seems even more curious to use them as instrument to construct a community of listeners. Nevertheless, this is what the study of the messages left on the answering machine of the French radio program Là-bas, si j’y suis reveals. The article explores first the particularities of this special type of audience participation, shows the differences to traditional forms of radio phone-ins and specifies the functions of the messages. For this purpose it draws on four primary functions (and four primary types) of messages: evaluations of the broadcast, assessments or statements related to a special topic, reports, and announcements. Secondly, it focuses on some devices which are used by the listeners to create an audience community through the broadcast and via the answering machine. For instance, putting up newsworthy topics for discussion, exposing standpoints and sharing first-hand knowledge are analyzed as resources for mutual information, alignment and the coordination of activities.