Thanks, I knew they were independant. Don't bother with it until you have other things done.

By the way, I will be glad to help post contributions if you tell me what to do.

Both are completely independant actually.
The site is made by me, the forum is not
The info about who is on the forum is actually "who asked a page of the forum in the last XX minutes".
I could do the same on the site, but there are already so many things to add I'll see how easily it can be added

I noticed that the logged-on users are shown on the forum but not on the site. Would it be possible to show them on the site as well without too much work ?