i met barbara rozgonyi a few years back at a worship leading & keynote session up in chicago. had some fab conversation and we've been blogger & twitter buddies since. she's much more advanced than i in the world of public relations & marketing in the social media spectrum, so in the past years i've learned a whole lot more from her than i taught in one chilly morning. she posted one of her presentations on slideshare on social media presence. this doesn't have her teaching it, which leaves out some of the fun, but within it you can find some very good numbers and warnings. for me too, it was a heads up that i probably need to pay attention to linkedin better (which as of now i just haven't done much with).