Other examples of social networking and professional development?

Greetings and Happy New Year to everyone!

I wonder if I can kick off 2008 by picking everyone's brains for a moment - I confess I have a selfish motivation behind this, but I think any answers I get may be of wider interest to others as well.

What I'm looking for is examples of organisations (or looser affiliations of individuals) who are using social software for professional development. Apart from RSA Networks, of course. So does anyone have any suggestions that I could follow up?

By social software I mean social networks (e.g. Facebook, Ning), blogs, wikis, shared bookmarks etc. And professional development can mean many things, but I'm mostly interesting in enhancing intrinsic job-specific skills on the one hand and broader scouting of collaborative/entrepreneurial opportunities on the other. The organisations could be membership-based, employers, educators or just self-organising networks.

The selfish part of this is that it relates to some work I'm doing for the National College for School Leadership, who are interested in extending the way they use social software with their constituency of school leaders. I'm happy to feed back the lessons from any leads that anyone gives me and share them with readers of this blog. Look forward to hearing from you if you can recommend any suitable examples (with contact details if possible). Our immediate deadline is 18th January, but happy to continue the discussion beyond then...