WordPress shortcode to insert content of another page http://alex.leonard.ie/2010/09/09/wordpress-shortcode-to-insert-content-of-another-page/

wp-shortcode-insert-content-another-page.php

/**
 * Create a shortcode to insert content of a page of specified ID
 *
 * @param    array        attributes of shortcode
 * @return     string        $output        Content of page specified, if no page id specified output = null
 */
function pa_insertPage($atts, $content = null) {
 // Default output if no pageid given
 $output = NULL;

 // extract atts and assign to array
 extract(shortcode_atts(array(
 "page" => '' // default value could be placed here
 ), $atts));

 // if a page id is specified, then run query
 if (!empty($page)) {
 $pageContent = new WP_query();
 $pageContent->query(array('page_id' => $page));
 while ($pageContent->have_posts()) : $pageContent->the_post();
 // assign the content to $output
 $output = get_the_content();
 endwhile;
 }

 return $output;
}
add_shortcode('pa_insert', 'pa_insertPage');


/* USAGE 
 * <?php echo do_shortcode('[pa_insert page="1228"]');?>
 */