Me tooo ... We have some Virtual Isps in our country so the IP's of different users can be same and some of users misuse this and I can not assess are they same or not . so a log can help very much .
i'd love a hack similar to this that indicated what threads a user had viewed / forums they'd accessed in the last X many days. It would be preferable to keep the database queries down if you could just set a certain users or user groups to watch.