This is a new plugin for the Rails Community that provides a customizable framework for cataloging and publishing user activity and social objects. We currently aim to provide support for microformats in HTML, Atom feeds, and compatibility with the open source DISO social networking implementation for activity discovery and consumption.
Here is a quickie for Rails 2.1:
./script/plugin install git://github.com/face/activity_streams.git
It may work on earlier versions of Rails as well. Don’t have git:
./script/plugin install svn://rubyforge.org/var/svn/activitystreams/trunk