Not sure if this has been found out yet but i was snooping through the Texture folders and i came across these weird (yet very retarded) faces. If you want to use them just rename the file into one of the faces that is already there. You can also change one of the Makeup Shop faces so u have people in your server have to buy them.
http://img210.imageshack.us/img210/2985/faces.th.png
