I can see how social networks on the web are a fantastic thing for those who have the time to be active in them -- lots of people with the same particular passion who want to discuss all of the minute details of that activity. However, I find it hard to carve out time to DO my passions, and don't want to spend that time discussing them. If anything, I tend to be a"lurker" rather than a poster in these forums.
I checked out three different sites for this thing. The "23 things on a stick" Ning met my expectations. It sounds like many of the program participants are facing the same challenges and surprises while working on their goals -- not enough time to fit everything in the day was a major theme. I also joined BakeSpace. I don't expect to be very active, but I always love a source of new recipes and it also has the potential as a resource to answer questions. I looked at (but didn't register for) Craftster. I found a wonderful forum thread there on crafting for charitable causes that gave me some ideas for channeling finished projects to a good home where they are needed. I may also use that site as a resource for future questions.