Set a different sidebar for all blog posts and archives on the Genesis Framework

genesis-blog-sidebar.php

<?php
/**
 * Swap default sidebar for the blog sidebar
 * on blog posts and archives.
 *
 * @author FAT Media
 * @link http://youneedfat.com
 */
add_action( 'genesis_after_header', 'mytheme_change_blog_sidebar' );
function mytheme_change_blog_sidebar() {
	if ( is_single() || is_page_template( 'page_blog.php' ) || ( is_archive() && ! is_post_type_archive() ) ) {
		//* Make sure blog sidebar has widgets
		if ( is_active_sidebar( 'blog-sidebar' ) ) {
			remove_action('genesis_after_content','genesis_get_sidebar' );
			add_action( 'genesis_after_content', 'mytheme_get_blog_sidebar' );
		}
		//* Output the blog slidebar
		function mytheme_get_blog_sidebar() {
			$site_layout = genesis_site_layout();
			//* Make sure the layout isn't full width
			if ( $site_layout == 'full-width-content' )
				return;
			echo '<div id="sidebar" class="sidebar widget-area">';
				dynamic_sidebar( 'blog-sidebar' );
			echo '</div>';
		}
	}
}

/** Register a blog sidebar */
genesis_register_sidebar( array(
	'id'		=> 'blog-sidebar',
	'name'		=> __( 'Blog Sidebar', 'mytheme' ),
	'description'	=> __( 'This is the default sidebar for the blog section.', 'mytheme' ),
) );