How to query the latest 5 posts and sort them by title?

$yourquery = new WP_Query('posts_per_page=5&orderby=title'); would do that.

Edit Added Answer

<?php 
$posts = new WP_Query('posts_per_page=5');
foreach($posts->posts as $post){
    $sorted[$post->ID] =  $post->post_title;
}
asort($sorted, SORT_STRING);

foreach($sorted as $k=>$v){
        //your loop -- use ID's for each item call
    the_title($k);
    the_content($k);
}
?>