We at LD Software have just release 'Who is Online' module for php-Nuke administrators.

This module is based on the "Who is Online Admin Module" version 3 by Jack Kozbial.
This version is Version 1 by LD Software, features of this version, ip lookup, bot recognition, Calculates total visitors, and splits the total into bots, visitors and members. Who is Online version 1 by LD Software, is the next level in development of this type of addon for php-Nuke, it makes use of a database table to store known ip addresses and display appropriate data when they visit.
You can download this module from LD Software you will need to register to download, which is free.
Support for this addon is available at LD Software Forums.