Actually, those are just the member groups. Users can have their own avatars.
What we do to use the images like that is we set the number of stars to 0 for each member group, then under rank name we use the following (from the Kokiri group): [b][color=black]Kokiri [img]http://i31.tinypic.com/e0iydu.jpg[/img][/color][/b]
This gives us a customizable name color for each group, as well as use an image rather than stars. Obviously we do a similar idea for staff
EDIT: Also, using this method solves the problem of having different stars for different skins as you are eliminating the stars all together.
Last Edit: Apr 10, 2009 10:55:11 GMT -5 by Tanshin