I appreciate the thought and desire to help the site get more exposure (Very much so). I assume the goal for any of this would be to either gain new users, rekindle the interest of old ones, promote Perl or a combnination of the three (Coming from a design and branding background I prefer specifics over 'to promote it'). However I'm having trouble understanding in what way social networking buttons would have the same or greater benefit than if members simply posted links to a favorite thread via their wall (twitter stream or linkedin page). The only real benefit I see is for the social sites themselves.

I would be in favor of some kind of custom URL shortener (or simply using an existing one). This way we still have a 'share' link available but it's not tied to any particular site. Maybe it's my design bias but I can see an  ever expanding group of 'social' buttons cluttering up the top of every post.