Think of a standard vocabulary playing a role similar to Graffiti that brought handwriting recognition to computers. Need to limit the gestures to a limited set that everyone agrees upon in order to grow under a shared understanding.
<actor><verb><indirect object><direct object> on <date/time> <context>
For example, <Ian> <posted> a <flickr> <photo> on <October 20, 2008> from <cell phone>
<Ian> - links to profile url
<posted> - uses activity stream verb, aggregator service template could use localization table
<flickr> - links to service
<photo> - links to object
Contacts
Blog
Status Message (twitter, facebook, plurk)
Bookmark (delicious, magnolia, stumbleupon, digg, reddit)
Photo (flickr, zooomer)
Video (YouTube, Hulu)
Audio (last.fm, pandora)
Events (upcoming, eventful)
*MySpace also currently makes a distinction when the event is a band adding a show as opposed to a regular event
Groups
Friend Categories
Forum Topic
Application (Also Mobile Application)
Profile (Profile Picture, Display Name, Interests, About Me, Personal Details, etc)
Custom Application Activities
Classified Ad
Poll
Karaoke Recording
Karaoke Artist
References