Just a note in case other people have this idea – a far, far better idea is to throw that stuff into a plugin file. It really isn’t much harder and it allows you to not lose all of your custom content whenever you upgrade/change your theme.
Create a php file in wp-content/plugins, say ‘my_header_content.php’
Put this in it:
<?php
/*
Plugin Name: My header content
Plugin URI:
Description: Add some custom header content
Author: Me
Version: 1.0
Author URI:
*/
function my_header_content() {
?>
<!-- Put your custom header content here, between the ?> and <?php -->
<?php
}
add_action( 'wp_head', 'my_header_content' ); // 'my_header_content' here is the name of the function above
?>
Then find the new plugin called ‘My header content’ in the plugins list and activate it. Voila, the ‘right way’.