The last Post of each author

Something like this should work. Of course, there might be a way to do this with less code:

global $wpdb, $table_prefix;
$order = 'user_nicename';
$user_ids = $wpdb->get_col("SELECT ID FROM $wpdb->users ORDER BY $order");

foreach($user_ids as $user_id) :
	$user = get_userdata($user_id);
	$level = $table_prefix . 'user_level';
	$user->user_level = $user->$level;
	if($user->user_level > 0) $all_authors[$user_id] = $user->display_name;
endforeach;

foreach($all_authors as $key => $value) :
	$author_id = op_author_name_id($key);
	query_posts("author=$author_id&showposts=1");
	if(have_posts()) :
		while(have_posts()) :
			the_post();
			the_title();
			// Add other post stuff
		endwhile;
	endif;
endforeach;