Remember which gallery you came from

attachment.php

<?php
/**
 * Gallery Image
 *
 * @package      BE_Genesis_Child
 * @since        1.0.0
 * @link         https://github.com/billerickson/BE-Genesis-Child
 * @author       Bill Erickson <bill@billerickson.net>
 * @copyright    Copyright (c) 2011, Bill Erickson
 * @license      http://opensource.org/licenses/gpl-2.0.php GNU Public License
 *
 */

// Remove Things
add_filter( 'prepend_attachment', '__return_false' );
remove_action( 'genesis_after_post', 'genesis_get_comments_template' );
remove_action( 'genesis_post_title', 'genesis_do_post_title' );
remove_action( 'genesis_before_post_content', 'genesis_post_info' );

/**
 * Attachment Content
 *
 */
function be_attachment_content() {

  global $post;
	echo '<p class="attachment-navigation">';
	previous_image_link( false, '&laquo; Previous' );
	$all = isset( $_GET['dcf_gallery'] ) ? get_permalink( esc_attr( $_GET['dcf_gallery'] ) ) : get_permalink( $post->post_parent );
	echo ' | <a href="' . $all . '">All Photos</a> | ';
	next_image_link( false, 'Next &raquo;' );
	echo '</p>';
	
	$image = wp_get_attachment_image_src( get_the_ID(), 'large' );
	echo '<p class="attachment"><img src="' . $image[0] . '" /></p>';
}
add_action( 'genesis_post_content', 'be_attachment_content', 5 );

/**
 * Add Gallery Arg to Adjacent Link
 *
 */
function be_previous_gallery_link( $output, $id, $size, $permalink, $icon, $text ) {
	$id = intval( $id );
	$_post = get_post( $id );

	if ( empty( $_post ) || ( 'attachment' != $_post->post_type ) || ! $url = wp_get_attachment_url( $_post->ID ) )
		return __( 'Missing Attachment' );

	if ( $permalink )
		$url = get_attachment_link( $_post->ID );
	if( isset( $_GET['dcf_gallery'] ) )
		$url = add_query_arg( 'dcf_gallery', esc_attr( $_GET['dcf_gallery'] ), $url );

	$post_title = esc_attr( $_post->post_title );

	if ( $text )
		$link_text = $text;
	elseif ( $size && 'none' != $size )
		$link_text = wp_get_attachment_image( $id, $size, $icon );
	else
		$link_text = '';

	if ( trim( $link_text ) == '' )
		$link_text = $_post->post_title;

	return '<a href="' . $url . '" title="' . $post_title . '">' . $link_text . '</a>';
}
add_filter( 'wp_get_attachment_link', 'be_previous_gallery_link', 10, 6 );

genesis();

single-gallery.php

<?php
/**
 * Gallery
 *
 * @package      BE_Genesis_Child
 * @since        1.0.0
 * @link         https://github.com/billerickson/BE-Genesis-Child
 * @author       Bill Erickson <bill@billerickson.net>
 * @copyright    Copyright (c) 2011, Bill Erickson
 * @license      http://opensource.org/licenses/gpl-2.0.php GNU Public License
 *
 */

/**
 * Gallery Images
 *
 */
function be_gallery_images() {
  $images = get_post_meta( get_the_ID(), 'be_gallery_images', true );
	$count = 0;
	foreach( $images as $image_id ) {
		$image = wp_get_attachment_image_src( $image_id, 'thumbnail' );
		$image = '<img src="'.  $image[0] . '" />';
		$class = 0 == $count || 0 == $count % 5 ? 'one-fifth first' : 'one-fifth';
		echo '<div class="' . $class . '"><a href="' . add_query_arg( 'dcf_gallery', get_the_ID(), get_permalink( $image_id ) ) . '">' . $image . '</a></div>';
		$count++;
	}
}
add_action( 'genesis_before_post_content', 'be_gallery_images', 20 );

genesis();