Prevent posts appearing more than once across all loops on your site

functions.php

<?php
// Paste the code BELOW this line into your child theme functions.

/**
 * Prevent posts appearing more than once across all loops on your site
 *
 * @author Reasons to Use Genesis
 * @link http://reasonstousegenesis.com/genesis-global-exclude/
 */
remove_action( 'genesis_after_entry', 'genesis_add_id_to_global_exclude' );
add_action( 'genesis_after_entry', 'rtug_add_id_to_global_exclude' );
function rtug_add_id_to_global_exclude() {

	global $wp_query, $_genesis_displayed_ids;

	$_genesis_displayed_ids[] = get_the_ID();
	$wp_query->set( 'post__not_in', (array) $_genesis_displayed_ids );

}

functions.xhtml.php

<?php
// Paste the code BELOW this line into your child theme functions.

/**
 * Prevent posts appearing more than once across all loops on your site (XHTML)
 *
 * @author Reasons to Use Genesis
 * @link http://reasonstousegenesis.com/genesis-global-exclude/
 */
remove_action( 'genesis_after_post', 'genesis_add_id_to_global_exclude' );
add_action( 'genesis_after_post', 'rtug_add_id_to_global_exclude' );
function rtug_add_id_to_global_exclude() {

	global $wp_query, $_genesis_displayed_ids;

	$_genesis_displayed_ids[] = get_the_ID();
	$wp_query->set( 'post__not_in', (array) $_genesis_displayed_ids );

}