Posts grouped by tag

<?php
// get the tag list
$taglist = get_terms('post_tag', 'hierarchical=0&orderby=name&hide_empty=1');
foreach ($taglist as $pftag) // iterate through the tag list
{
        // get 2 posts belonging to the tag -- ONLY the slug works to filter by tag
        query_posts('tag='.$pftag->slug.'&posts_per_page=2&orderby=date');?>
        <!-- make a linked heading with the tag name -->
        <h3><a href="/tag/<?php echo($pftag->slug); ?>"><?php echo($pftag->name); ?></a></h3>
        <!-- make loop using custom action for output -->
        <?php while (have_posts()) : the_post();
                purplefrog_excerpt_tile();
                endwhile;
} ?>