Unfortunately, the activities service didn’t make it into 4.4 because there wasn’t enough time for it to pass on from kdereview into kdebase. This means that it was returned to playground for further processing. :)
The service has grown a bit and now it exposes a few more methods like linking activities to other nepomuk resources (documents, places…).
Since the service is not really useful by itself (from the user’s point of view), it will need some kind of UI. The main UI will be Plasma and the ZUI replacement which will be one of the Tokamak4’s main topics.
For the time being, I made a KIO slave shown in the picture above. It lists the defined activities and the resources linked to it. At the moment, the resources are limited to Applications, Documents, Places and Contacts (I’ve just realized that those are the same sections that are in Lancelot - completely by accident).
The data shown in the picture is a garbage data I put into nepomuk for the sake of testing (no sane person would put Thumbs.db in the work-related documents. :)