[php] WordPress query single post by slug

For the moment when I want to show a single post without using a loop I use this:

<?php
$post_id = 54;
$queried_post = get_post($post_id);
echo $queried_post->post_title; ?>

The problem is that when I move the site, the id's usually change. Is there a way to query this post by slug?

a less expensive and reusable method

function get_post_id_by_name( $post_name, $post_type = 'post' )
{
    $post_ids = get_posts(array
    (
        'post_name'   => $post_name,
        'post_type'   => $post_type,
        'numberposts' => 1,
        'fields' => 'ids'
    ));

    return array_shift( $post_ids );
}

How about?

<?php
   $queried_post = get_page_by_path('my_slug',OBJECT,'post');
?>

As wordpress api has changed, you can´t use get_posts with param 'post_name'. I´ve modified Maartens function a bit:

function get_post_id_by_slug( $slug, $post_type = "post" ) {
    $query = new WP_Query(
        array(
            'name'   => $slug,
            'post_type'   => $post_type,
            'numberposts' => 1,
            'fields'      => 'ids',
        ) );
    $posts = $query->get_posts();
    return array_shift( $posts );
}