Maybe I'm missing something, but I can't seem to figure out how to add my own avatar to the list. I see a couple people know how but I'm not a PHPNuke pro. A little help, someone?
Do you see a "Profile" link at the top of the forums window? You can change your avatar there, and you should be able to upload an avatar from your local workstation.
Let me know if you have any more questions or troubles with this!