On a recent project I had to show the total number of comments posted using Disqus for each node on a page. What the page did was loop through a bunch of nodes and render the teaser view of each node. The teaser was shown by rendering node.tpl.php, and in that file I had to display the total number of comments. Clicking a teaser view took me to the full page of the node that also contained the Disqus commenting box.
To do this I had to do add code in two places:
<a href="<?php print url(drupal_get_path_alias('node/' . $node->nid));?>#disqus_thread"></a>