Zeitgeist is a service which logs the users's activities and events (files opened, websites visites, conversations hold with other people, etc.) and makes relevant information available to other applications. It has support for tagging items (both automatically by the data provider and manually by the user) and bookmarking items. Further, it is able to establish relationships between items based on similarity and usage patterns (this feature isn't implemented yet). This project maintains Zeitgeist's backend. The GUI is maintained in the https://launchpad.net/gnome-zeitgeist/ project.
Created attachment 198109 [details] zeitgeist-0.2.0.ebuild Initial ebuild for zeitgeist-0.2.0 GUI should come soon
An updated ebuild plus one for gnome-activity-journal is in my dev overlay.
I have just committed gnome-extra/zeitgeist-0.7 to portage. Closing the bug.