UPDATE: I gave an updated version of this presentation to the Atlanta Drupal User Group. You can get the newer slides here.
I gave a presentation on Social Networking at DrupalCamp South Carolina on June 13th, 2010 (hosted by the SouthEast LinuxFest). Here are the slides I presented (complete with my notes on them) in various formats, as well as a link to the demo site (feel free to play around) and the downloadable Feature I exported based on the demo site.
Demo site: http://sndemo.dev3.webenabled.net/
Feature: http://community.featureservers.org/project/self-social-network (also attached)
View slides online: http://www.slideshare.net/mediacurrent/social-networking-in-drupal-isaac...
If you want to download the slides, I recommend the PPTX.
Finally, thanks to Mediacurrent and Doug Vann for making it possible for me to give this presentation.