I'm finding it interesting the difference with online social networking and personal networking groups 'on the ground' as it were. It is almost like two different animals, and yet the purpose for both would seem to be the same.
Interestingly, I'm exploring a personal network for people to use online facilities to manage their personal network (on the ground) with online functions and a profit sharing component. It is available for members to join in any location, and seems to be an interesting way to combine in-person and online into a system that allows one to create a strong, systematic approach to endorsing those who are known to us as being reliable, ( and to whom we would refer now to the appropriate people), and allowing a way to monetize that as well. Since it is being put together by someone who is not involved online, it is going to be interesting to see how that develops.
For many trades people and bricks and mortar businesses, social networking is not even in their vocabulary. And meeting at regular functions is outside the constraints of their working day schedule. This might be a nice way to open up the door to the benefits of networking for these people who have really been doing it on their own up till now.
Let me know if this is something that might interest you.