There was a "Wikipedians" group which was apparently started for "networking" (which in practice seemed to mean spam blasts), per
http://davidgerard.co.uk/notes/2009/04/16/wikipedians-on-linkedin/
But there's at least a couple more groups which are sincere and were just put together by Wikipedians (i.e. not Foundation-official), e.g.
http://www.linkedin.com/groups?about=&gid=104879
I have no idea about how to consolidate LinkedIn groups, but for the moment I suggest it would be an idea to make a wiki page (presumably on meta) for these. If there isn't one already. Same on other social networks. Anyone?
- d.