Add pinterest link after each post, only on singles.

functions.php

<?php

add_action( 'genesis_post_content', 'child_add_pinterest_link', 15 ); 
/**
 * Add pinterest link after post.
 *
 * Conditionally limited to single post. Remove the first conditional
 * to make it show up on archive pages too.
 * 
 * @since 1.0.0
 *
 * @author Gary Jones
 * @link   https://gist.github.com/1756487 
 */
function child_add_pinterest_link() { 
    
    if ( ! is_single() )
        return;

    // Prepare URL
    $url = add_query_arg(
        array(
            'url'   => get_permalink(),
            'media' => genesis_get_image( array( 'format' => 'url' ) )
        ),
        'http://pinterest.com/pin/create/button/'
    );
    
    // echo markup - be aware that this is invalid markup!
    // count-layout can be horizontal, vertical, or none.
    echo '<a href="' . esc_url( $url ) . '" class="pin-it-button" count-layout="horizontal">' . __( 'Pin It', 'child-theme-domain' ) . '</a>';

}

add_action( 'wp_enqueue_scripts', 'child_add_pinterest_script' );
/**
 * Enqueue script for pinterest pin it button.
 *
 * Conditionally limited to single post. Remove the first conditional
 * to make it show up on archive pages too.
 * 
 * @since 1.0.0
 *
 * @author Gary Jones
 * @link   https://gist.github.com/1756487 
 */
function child_add_pinterest_script() {

    if ( ! is_single() )
        return;

    wp_enqueue_script( 'pinterest', 'http://assets.pinterest.com/js/pinit.js', false, false, true );
    
}