A really simple userscript to replace the usernames with their current avatar in Campfire.

campfire-avatars.css

img.plain-avatar {
  border-radius: 10px;
}

a.image img {
	border-radius: 10px !important;
	box-shadow: #808080 3px 3px 3px !important;
}

campfire-avatars.js

function add_avatars() {
  $$('.author').each(
    function(elem) {
	var avatar = elem.dataset.avatar;
	var nm = elem.dataset.name;
	if (avatar !== undefined) {
		elem.update('<img src="' + avatar + '" width="35" height="35" title="' + nm + '" class="plain-avatar" />');
	}
 	
   });
}
 
add_avatars();
 
Campfire.Transcript.prototype.insertMessages_original_2 = Campfire.Transcript.prototype.insertMessages;
 
Campfire.Transcript.prototype.insertMessages = function() {
	messages = this.insertMessages_original_2.apply(this, arguments);
	add_avatars();
	return messages;
};

The CSS didn't work for me. Not sure why.

hmmmm, I added it as another style and it seemed to work fine.