Best features of social networking:

Creating timelines of what those in your network are doing – particularly good in Twitter
Creating events and being able to connect with participants – e.g. online conferences, Facebook events
Serendipitous exchange – knowing what others in your network are doing e.g. uploading photos, status updates
Opportuniteis to informally connect with ‘weak ties’ in business – i.e. friends of friends.
Ease of use to comment, respond, sign-up or comment.