is_follow_each_other.user.js

// ==UserScript==
// @name          is follow each other
// @namespace     www.dolpen.net
// @include       http://twitter.com/*
// @include       https://twitter.com/*
// @exclude       http://twitter.com/invitations/*
// @exclude       http://twitter.com/settings/*
// @exclude       http://twitter.com/goodies/*
// @exclude       https://twitter.com/invitations/*
// @exclude       https://twitter.com/settings/*
// @exclude       https://twitter.com/goodies/*
// @require       http://jqueryjs.googlecode.com/files/jquery-1.3.2.min.js
// ==/UserScript==
(function(){
	var my_name = $("span#me_name").text();
	if(my_name=="")return;
	$(".status-content>strong").each(function(){
		var self=$(this);
		var your_name = self.text();
		GM_xmlhttpRequest({
			method: 'GET',
			url:'http://api.twitter.com/1/friendships/exists.json?user_a='+my_name+'&user_b='+your_name,
			onload: function(xhr){
				if(eval("(" + xhr.responseText + ")"))self.after("*");
			}
		});
	});
})();