<script type='text/javascript' src='
getfirebug.com/releases/lite/1.2/firebug-lite-compressed.js
'></script>
Maybe even make it a little more classy:
<?php if (activate_firebuglite) { ?>
<script type='text/javascript' src='
getfirebug.com/releases/lite/1.2/firebug-lite-compressed.js
'></script>
<?php } ?>
Then place an enable and disable in the XML of the template would be a great idea so us helpers can use FireBug Lite in IE, etc.