Comment Count with Custom Image

Images could be added using a combination of markup, template tags and CSS.

MARKUP:

<?php comments_popup_link('<span class="none">Comment on '.$post->post_title.'</span>', '<span class="one">1 Comment on '.$post->post_title.'</span>', '<span class="lots">% Comments on '.$post->post_title.'</span>','postcomment','Comments are off for '.$post->post_title); ?>

CSS:

.postcomment {padding-left:20px;padding-bottom:10px;}
.postcomment .none {background:url(images/none.gif) no-repeat left top;}
.postcomment .one {background:url(images/one.gif) no-repeat left top;}
.postcomment .lots {background:url(images/lots.gif) no-repeat left top;}

The above assume icons of around 16 x 16px in your theme’s images folder. The padding might need tweaking a bit and you may need some margins added to push the icon away from your header text but the above should cover the basics.