Just out of interest John &Co.,
There are currently 15 member(s) and 23 guest(s) on the boards.
I believe you determine the ID of users with multiple usernames from the IP address. Is this correct?

Do you log the IP addresses of "Guests" as well?

If so, how many the 23 guests are actually members without cookies?

My "supervisor" isn't a member but reads the forums now and then when I mail pages of interest to him. His IP address will be the same as mine - as will anyone else accessing from my office.