For drupal platform I've found interesting mod called activity.
The Activity module keeps track of the things people do on your site and provides mini-feeds of these activities in blocks, in a specialized table, and via RSS. The module is extensible so that any other module can integrate with it. The messages that are produced are customizable via the admin interface and are context sensitive.
Url:
http://drupal.org/project/activityI'm aware that integrating such mod in 4images system would take some time, but since this looks like very interesting mod, it's worth to.
Is anyone willing to give it a shot?