Multipresence allows each human user, in, for example, a distributed groupware system like the internet, to have source and sink presence in multiple spaces at once, by designating an arbitrary number of representatives as "self." Operations which filter information streams by blocking sources or sinks are useful for distributing and focusing attention and presence. Such "narrowcasting" operations can be modeled as an extended "media mixer": source operations apply to first-order mixing; sink operations apply to second-order mixing. The value of such an multipresent interface, articulated with narrowcasting operations, can be characterized as exponential in the number of users, the power set of the number of coteries. Audio windows are, in analogy to graphical windowing systems, an idiom for managing multiple duplex streams of information, as in a teleconference, chatspace, or virtual concert. We are developing audio windowing interfaces to groupware and VR-style applications, deployed on both workstations and mobile devices, and present a multipresenceenabled audio windows media mixer. Keywords: CVEs (collaborative virtual environments), distributed virtual environments, groupware, shared virtual worlds.