I am a big fan of LinkedIn, I think it is one of the most useful 'social networks' on the web (though I hate that term and don't think it applies well to LinkedIn). I recently joined the Nike Global Alumni Network on LinkedIn to allow me better access to past co-workers without having to add them directly to my network.
Last week I apprently helped inspire the creation of a new LinkedIn group for Portland, Oregon area technology professionals. If you are interested in joining, follow the link below:
-Jeff the Great