Plugin Name: AddThis
Plugin Description: The #1 Bookmarking & Sharing Service
 
Plugin URL: http://addthis.com/
Author: tylerabell
Author URL: https://www.intensedebate.com/people/tylerabell
Date Added: September 10th, 2009

Code:
var id_addthis_posts_plugin = {};

// Initiate AddThis drop-down(s)
id_addthis_posts_plugin.load_addthis_js = function() {
	/* AddThis globals */
	a2a_linkname = document.title;
	a2a_linkurl = location.href;

	var s = document.createElement('script');
	s.src = "http://s7.addthis.com/js/250/addthis_widget.js";
	document.getElementsByTagName('head')[0].appendChild(s);
};

// Insert AddThis button below each comment
id_addthis_posts_plugin.insert_share_button = function() {
	var container = document.getElementById('idc-container');
	var button_cont = document.createElement("div"),
		button_link = document.createElement("a"),
		button_image = document.createElement("img");

	button_cont.style.display = "block";
	button_cont.style.margin = "15px 0";

	button_link.className = "a2a_dd";
	button_link.href = "http://addthis.com/bookmark.php?v=250";

	button_image.src = "http://s7.addthis.com/static/btn/v2/lg-share-en.gif";
	button_image.width = 125;
	button_image.height = 16;
	button_image.border = 0;

	button_link.appendChild(button_image);
	button_cont.appendChild(button_link);

	container.insertBefore( button_cont, container.firstChild );
	container.insertBefore( button_cont, container.firstChild );

	/* Initiate drop-down */
	id_addthis_posts_plugin.load_addthis_js();
};

// IntenseDebate Filters
id_add_action('idcomments_init', id_addthis_posts_plugin.insert_share_button);

CSS:
N/A