This is all related to the benefits of collaborative browsing which I’ve covered before in “Collaborative Browsing” and “Social Media Rooms”. The future of the web will become less about isolation and more about group activities and interactivity.
Here’s a short screencast that shows you how it works.
Glue 4.2 Overview from AdaptiveBlue on Vimeo.
For more information checkout these two excellent posts on Glue:
Glue Gets Facebook Connect Support
Glue Binds social networks with the Semantic Web