1. A method executable by each of a plurality of clients operating as peers in a local area network to reduce consumption of network bandwidth on an external network during streaming of a media stream obtained from an external network repository, the method comprising: the client organizing in a linked structure with the other clients, wherein each of the plurality of clients in the linked structure has a different set of media streamlets obtained from the external network repository, and wherein each streamlet is an individually-addressable data file containing an identifiable portion of the media stream having a particular quality, wherein each client is linked to at least one other client and the plurality of linked clients are located within the local network; each client distributing streamlet mapping information to linked receiving clients, the streamlet mapping information representing location of local media streamlets stored by the plurality of clients; each client applying a priority policy rule defining streamlet quality priorities and network priorities that are used when obtaining media streamlets for media playback; and during playback of the media stream, retrieving additional media streamlets based on the priority policy rule from the plurality of clients within the local network using the streamlet mapping information if the additional media streamlets are available from clients within the local network, and otherwise obtaining the additional media streamlets from the external network repository.