Link which leads to comments
Creating a link like this will not create the desired output. When looking at the l() function comments on the Drupal API page, the following is suggested to make internal anchors work:

l(t('Comments'), $_GET['q'], array('fragment' =&gt; 'comments'));


What happens is you tell Drupal to create a link to the current page, and add #comments as an anchor (fragment).

This means you can also link to the comments from other pages, by simply changing the $_GET['q'] parameter to the desired path.