wp_list_bookmarks comma seperated

I’m using wp_list_bookmarks function to pull in 3 bookmarks. I’d like to place a comma after the first and second link.

Here is my code.

<?php wp_list_bookmarks('title_li=&categorize=0&category_name=About Me&orderby=rand&limit=3&between=&before=&after='); ?>

Here is my site: http://www.line47.com

Any help is appreciated!
Thanks!