Get attachments

gistfile1.php

<?php
/**
 *
 * Gets media attached to a post
 * 
 * 
 * @global type $post
 * @param type $post_id
 * @return type array
 * @todo revise method to be more flexible
 * 
 */
function get_attachments_by_post( $post_id, $file = false, $single = false, $image_size = "Full Size" ) {

        global $post;
        $out = array();

        $args = array(
            'post_type' => 'attachment',
            'numberposts' => null,
            'post_status' => null,
            'post_parent' => $post_id
        );
        $attachments = get_posts( $args );
        if ( $attachments ) {
            
                foreach ( $attachments as $attachment ) {
                    if($file){
                        $out[] = get_the_post_thumbnail( $post_id, $image_size );
                    }else{
                         $out[] = get_attachment_link( $attachment->ID );
                    }
                }       
        }

        if ( $single && is_array( $out ) )
			return isset($out[0])?$out[0]:'';
		else
			return $out;
}