gistfile1.js

// HTML for the share on Tumblr link:
//
//<a href="http://onefoolishact.com" title="Website title" data-description="The description goes here" class="tumblr" style="display:inline-block; text-indent:-9999px; overflow:hidden; width:31px; height:31px; background:url('http://platform.tumblr.com/v1/share_3.png') top left no-repeat transparent;" target="_blank">Share on Tumblr</a>
// 
// and before the </body> add:
//
// <script type="text/javascript" src="http://platform.tumblr.com/v1/share.js"></script>

$('a.tumblr').click(function(e){
  	 
    //We tell our browser not to follow that link
    e.preventDefault();
		 
    //We get the URL of the link
    var loc = escape($(this).attr('href'));
    var title = escape($(this).attr('title'));
    var description = escape($(this).attr('data-description'));
    //We trigger a new window with the Twitter dialog, in the middle of the page
    window.open('http://www.tumblr.com/share/link?url=' + loc + '&name=' + title + '&description=' + description +'&', 'facebookwindow', 'height=450, width=550, top='+($(window).height()/2 - 225) +', left='+$(window).width()/2 +', toolbar=0, location=0, menubar=0, directories=0, scrollbars=0');
		 
});