Social plugins let you see your friend’s activity on Google Plus across the web.
Activity Feeds explore the recent activity users have taken on Google Plus. This expose users to the possible actions that can be taken on Google Plus. Users can readily see what others are doing. Google Plus feeds are real-time, the information has timely relevance.
The Live Stream plugin lets your users share activity and comments in real-time.
The Activity Feed plugin shows users what their friends are doing on Google Plus.
http://blog.svnlabs.com/2011/08/google-activity-feeds-widget/
