Last date/time force update

[Jawelin]

Last visit/activity values seem to be updated only when creating a new session.
This way, if I'm always logged in or my session doesn't expire, that values aren't updated.

First, is this right ?

Well. I created some hacks based upon lastvisit/lastactivity to perform something (actually they checks if some forum light bulb is 'on'). So I would force sometimes the update of that values, for example when visiting certain forums (forumdisplay.php)

What should be the cleanest way to do so ?
Where ?

Thank you very much.
Bye