We often move our WordPress install around to different machines, and wanted to know what host the WordPress install serving the page was. We are using the mon-caheir theme, as part of MCJ, but this should work similarly with other themes.
Edit wordpress/wp-content/themes/mon-cahier/header.php, find the line that contains site-description, and change it so it looks like this:
<h2 class=”site-description”><?php bloginfo( ‘description’ ); ?> – <?php echo gethostname(); ?></h2>
Now we see the hostname after the blog description: