If you just want an icon to show up for staff, you can do this:
Open index.php -
Find:
PHP Code:
$username = "<b><i>$loggedin[username]</i></b>";
Replace with:
PHP Code:
$username = "<b><i>$loggedin[username] <img src=\"http://www.yourforums.com/images/admin.gif\"></i></b>";
THE CODE APPEARS TWICE - DO THIS TWICE!
This is for the ADMIN icon. Change the image path to whatever you want.
Then, find:
PHP Code:
$username = "<b>$loggedin[username]</b>";
Replace with:
PHP Code:
$username = "<b>$loggedin[username] <img src=\"http://www.yourforums.com/images/mod.gif\"></b>";
THE CODE APPEARS TWICE - DO THIS TWICE!
This is for the MODERATOR icon. Change the image path to whatever you want.
For this to work, you need to set in Admin CP, vB Options, for the staff username bold and italics to ON.
As for other users, like I said, it's a JOIN feature if you use the custom profile method.
I think there is a hack that allows members to have small icon next to their username on the homepage. Maybe modify that for your purposes.