Gee, J. P. (1999). An introduction to discourse analysis theory and method (2nd ed.). New York, NY: Routledge.
While this is a book about discourse analysis it is really about social interactions (both spoken and written) and how they shape our world. Read this in light of identity and its relationship to community. Gee frames his thinking in terms of Discourses. For your purposes think about not only the discourse as the content of the communication, but like Marshall McLuhan, think about the medium as message. What does discourse when using a different tool do to the identity of the communicators? How does the tool shape the discourse and vice versa?
Find the readings here.