Recent work on the occurrence of "uh" and "uhm" in ordinary talk-in-interaction is concerned almost exclusively with its relation to trouble in the speech production process. After touching briefly on this environment of occurrence, this conversation-analytic article focuses attention on several interactional environments in which "uh(m)" figures in other ways--most extensively on its use to indicate the "reason-for-the-interaction's-launching." The underlying theme is that accounts for what gets done and gets understood in talk-in-interaction must take into account not only its composition, but also its position--not only with respect to the grammar of sentences, but also with respect to the organization of turns at talk, of action sequences encompassing multiple turns at talk, and of occasions of talk, all of which are demonstrably oriented to by speakers in their production of the talk and by recipients in their analyzing of the talk. (Contains 11 footnotes.)