This my setup
First create a folder called "shoutbox2 and copy content of rar to it.
then
You will need to put staff_shoutbox.php in ==> include/plugins/ and put staffshoutbox.php==> /
Depending on your db you might need to run a MYSQL query.. called "staffshoutbox"
When Done create a new plugin and add
Plugin Name: staff_shoutbox
Plugin Title: staff_shoutbox
and give the appropriate credentials and Sort Order.
As far as I can remember that's it
PS there are files missing from the rar as far as I can gather.. could be wrong though.
DO not use a Iframe to display your staffbox unless your shoutbo.php or shoutbox.php is protected by a admin/mod group session other wise it would be pointless