[eluser]WanWizard[/eluser]
No, you could use the session table for that, but it requires some modifications.
Best thing to do is to copy the session library to application/libraries, then modify it to include a last_updated timestamp (that get's updated every UPDATE query), and a user_id field, that you set from your is_logged_in() method (use 0 if no user is logged in).
Once you have that, you can run a query like
Code:
SELECT user_id, MAX(last_updated) as timestamp FROM sessions WHERE user_id > 0 GROUP_BY user_id
to get the timestamp of the last page request for every user.