function author_avatar() {
if (is_single()) {
 echo '<div style="float:right; padding-left: 5px;"><script type="text/javascript" src="http://tweetmeme.com/i/scripts/button.js">
</script><script src="http://digg.com/tools/diggthis.js" type="text/javascript"></script></div>';
 }
}
add_action('thesis_hook_before_headline', 'author_avatar');