Title/Tooltip for Blogroll Images

I’m running 2.6.1 and Have recently starting using the following piece of code in a PHP widget to list my blogroll, using images:

<?php

wp_list_bookmarks('title_li=sdfs&category_before=&category_after=&before=<div class="alignleft" style="margin:0px;border:none">&after=</div>&category_after=<br  clear="all" />'); 

?>

This works fine except I have to admit that some of my images don’t make it obvious which blog they link to. I’d like for the blog name to show when you hover over the image. I’ve searched the forum and looked in the codex and I don’t see anyway to do this. Any suggestions?

This can be seen in action at http://queerandloathing.com