I have not seen or at least missed if there is a plugin to show who's on line and maybe some login stats

There is no such plugin. Zenphoto also does not really store who currently is online. It store the date of the current login (which does not mean the user is online), the last login, the last password change and the last change to a user account in general.

ok just thought I would be a good plugin idea

If there were to be such a plugin one would need a definition of "on line". The best that a website can do is note the last page fetch time of a particular user. So how long do you wait before you decide he is no longer :on line"? I suppose that could be an option of the plugin. But I would like a starting point.

The plugin would be relatively easy to build. All it has to do (besides presenting the data) is register a couple of filters whose processing would log the access time of the user.

I might build such a plugin if there is general interest.

I would be interested!

So, what should the expiration duration be?

FYI we decided that we will add a new column "lastvisit" and support this natively. `zp_loggedin()` will handle this. The time frame when to update the table value will be an option (in seconds) and it will be possible to disable it completely.

So any theme, plugin or template function might use this and decide what is "currently online".

The change is in the 1.5.8b support build now (setup needs to be run) and the value can be used via the user class method `getLastVisit()`.