Thanks to Daniel Walker's response to this post i figured it out.
In the book it says you simply echo back the variable like so...
<?php echo "$Author"; ?> // Which doesn't work (for me :)
However, for me (Different version of PHP?) this does work...
<?php echo ($_GET['author']); ?>
If anyone has an explanation for this i'd appreciate it. I don't *think* it's an error in the book?