A great feature for activities would be time tracking. It could be an external app or widget. The idea is that the desktop keeps track what activities you are working on during the day. Time should be counted while an activity is active and the user is not idling for more than 30 seconds. At the end of the day(week/etc. you can obtain a nice summary on which activities consumed most of your workday. The beauty of this feature is that the user does not need to use additional tools/input to keep track of her activities, which is a prominent drawback of existing time tracking solutions. Reproducible: Always
*** This bug has been marked as a duplicate of bug 269752 ***