What is a "user"? What is "current"? I think you'll find both of those are ultimately meaningless. So you might as well just put a random number up there.

A user is not an IP address. AOL proxies show many hits from different IP addresses even in the same session. NAT-ted boxes all appear to be the same IP address. So unless you have an explict "login", you don't have knowledge of a "user".

And as for "current", a web session doesn't really exist, since what you really have is a bunch of independent hits.