Links/Bookmarks Custom Output

wp_list_bookmarks() doesn’t let you do too much customizing to the link data.

I was looking at this, but I’m not sure how to also organize my links by their category.

<?php $bm = get_bookmarks(); ?>

    <?php foreach ($bm as $bookmark) { 

	       $output .= "<li>{$bookmark->link_name}</li>";

          } 

	echo $output;

	?>

Any help would be appreciated.