In the default and classic themes, the wp_head hook is called with
<?php wp_head(); ?>. So, by analogy, wp_footer should be
<?php wp_footer(); ?>, but when I do this I get an 'undefined function' parse error. Turns out that we have to use
<?php do_action('wp_footer'); ?> instead. No problem with that, but why the different formats? These unexplained anomalies just make things harder for those of us who are trying to do things properly.
I wonder how many of the current competition themes (other than those based on Kubrick) even bother with plugin hooks. Is it honestly worth my while to keep hammering away at this?