I spoke at Wikimania 2007 about Enhancing wiki with social networking tools. Below are the slides I used for the talk; available under the CC-BY Canada 2.5 except for logos which aren't mine to give.
Note: I make pretty cruddy slides to begin with, but these might be the worst slides I've ever done. No fault of the out-of-the-box template I got from OpenOffice, of course.