i am still drinking in the theories put forth by Penelope Eckert  in her book, Linguistic Variation As Social Practice, and have listed and/or summarized a few below:

• No community exists in a vacuum and it is the individual speaker that brings life to language.
• Speaker as constituting rather than representing social categories
• The ’social meaning of variation’ is not just a reflection of membership, it is what makes membership in categories meaningful
• This theory treats:
         -the speaker as a linguistic agent
         -speech as a building of meaning
         -and the community as mutually engaged in a meaning-making enterprise (1999:4)
• "The social meaning associated with variation is local – it has to do with concrete places, people, styles, and issues" (1999:4)

I have only begun Eckert’s book, but have also read a bit of Bell, which so far seems to be in line with her theory. He also takes into consideration the audience in his taxonomy of audience members: addressees, auditors, overhearers, eavesdroppers, and referees.

Bell’s taxonomy has interesting implications as to self-presentation and discourse in blogging because there are different types of audiences – those to whom you are ’speaking’, those of whom you are aware (part of your self-defined/identified network), those of whom you are vaguely aware (periphery members and ‘free-movers’ within your network), and the public audience which is part and parcel of speaking in a public space.