WP: Custom fields output. Input: use page editor metabox

Custom fields - output

/* simple output of value (url) custom field with key "post-icon", in your page/template.
*/
<?php echo get_post_meta($post->ID, 'post-icon', true); ?> // 'true' means string instead of array

/* use 2 */
<img src="<?php echo get_post_meta($post->ID, 'post-icon', true); ?>" alt="Icon for Post #<?php the_ID(); ?>" />

/* use 3 - outside of the loop (eg in sidebar or...), make new loop */
<?php query_posts('showposts=10&offset=0'); ?>
<?php if (have_posts()) : while (have_posts()) : the_post(); ?>

  <a href="<?php the_permalink() ?>" title="<?php the_title(); ?>">
    <img src="<?php echo get_post_meta($post->ID, 'post-icon', true); ?>" alt="Icon for Post #<?php the_ID(); ?>" />
  </a>

<?php endwhile; endif; ?>

/* use 4 - display if it exists */

<?php $image = get_post_meta($post->ID, 'url', true);  
if($image) : ?>
  <img src="<?php echo $image; ?>" alt="" />
<?php endif; ?>

/* use 5 - multiple values */
<?php $songs = get_post_meta($post->ID, 'songs', false); ?> // false to get array
	<ul>
		<?php foreach($songs as $song) {
			echo '<li>'.$song.'</li>';
			} ?>
	</ul>