Discussion Forum—A Way with Words, a fun radio show and podcast about language

I have carelessly set my EFL business students an exercise on business recruitment through social networking sites (Facebook / Twitter / LinkedIn and Viadeo / et al. [must set up that website some day]); and I find myself stumped when I try to say what someone who posts information about themselves on one of these sites is called. Maybe one should look for something that also covers bloggers (at least amateur ones, if the distinction can be drawn) but I would settle for the users of the commercial sites I have named.

Facebooker or Twitterer are straightforward, but too site-specific (and I have an uneasy feeling that there is already a more widespread name for people who use Twitter - 'Twits' ?). Clearly one could say 'social networkers'; and one user whom I took to be knowledgeable suggested to me 'web2master', but the only use of that I have found is an obscure beginner blogger who specializes in south-east Asiam actresses, which leaves me uncertain.

I would be grateful for suggestions - and of course if the word does not already exist and you invent it, think of the glory (I think "stupid b's" is already taken).