I have just created a new id on Linkedin for the simple reason that Linkedin has not been paying attention to the explosion of groups. As a conference guy I have an interest in a lot of places. The linkedin groups are one place that I like to monitor. But the groups are all over the place and tracking the right ones to connect to has become painful. Big numbers does not mean good ideas and for industry country based groups are sometimes restrictive in how they post.
But rather than be stuck trying to choose do I want to track Smart Grid more than Green Initiatives I have decided my solution is in multiple email accounts.
I would rather have a curation tool, but alas that is not in the cards right now.