You may be interested in some work along similar lines in other disciplines. Donald MacKenzie, sociologist at Edinburgh University, Scotland, has written recently on the diffusion of agency across a group of people and their information/software tools in modern financial trading. He says it is not an individual trader who acts (has agency) but a group, which comprises people outside the firm as well as inside, together with their artefacts.

These ideas have also arisen in theoretical computer science for the design of distributed computer systems, in the theory of co-ordination artefacts of Andrea Omicini and colleagues at the University of Bologna, in Cesena, Italy. (See my blog entry for 25 August 2005 for links to the work of both these people.)

From my limited knowledge of anthropology, it would seem that there are interesting parallels between ideas of extended human intelligence, sociality and agency to related beliefs in other cultures.