Include a metabox in the ‘home’ screen of a custom post type? If not, then the dashboard page?

Try something like this. I haven’t actually done this yet, it is something I was looking into, so please let me know how it goes.

add_action(‘wp_dashboard_setup’, ‘custom_dashbox’);

    function custom_dashbox() {
    global $wp_meta_boxes;

    wp_add_dashboard_widget('widget_slug','Widget Name', 'widget_display','widget_submission');
    }

    function widget_display() {
    echo '<input type="text" name="youtube_id" /><br/>
<input type="submit" name="submit_youtube" />';
    }

function widget_submit() {
//Do what you need to do with your youtube id possibly:
if (get_option('youtubeid'))
{
update_option('youtubeid',$_POST['youtube_id']);
}
else {
add_option('youtubeid',$_POST['youtube_id']);
}
}