Finding Quality Professional Connections around the world--LinkedIn Social Networking

I need to find quality professional connections around the world.  Looking to social networking for a solution, LinkedIn.com seems to be a very good solution.  There are millions of people connected via the site.  Many of the discussion groups put me in touch with professionals in the areas I am looking for.  Alumni networks put me in touch with professionals who share a corporate history with me from the global workplace.

LinkedIn offered me the opportunity to start my own discussion groups.  I created three to gather together people interested in three different projects I am currently working on.  I've just dissolved one of these groups due to apparent lack of interest (at the moment) and have sent an announcment to members of the Audio eBooks for Learning to see if people want that group to continue.  My newest group is DrM-Language-Network so that people who choose to work with me on my latest project, making affordable online language learning programs available to learners throughout the world, can join with me to share ideas and to celebrate sucesses.

I've joined several pre-existing LinkedIn discussion groups so that I can invite people to work with me or to refer me to others who may want to be involved in my current project(s).  Some of these people have also joined my "primary" LinkedIn network.

Many of the people who are already in my primary LinkedIn network are the type of professionals I enjoy working with.  LinkedIn is one place to find quality professional connections.  Presently this seems to be the most direct and effective means, though I am open to learning about more.