<?php
$network_query_posts = network_query_posts( array( 'post_type' => 'posts', 'posts_per_page' => 25 ));

    if( network_have_posts() ) {

        while( network_have_posts()) {
            network_the_post();

            // Get the author id for the current post
            $id = network_get_the_author_id();
            $author = get_userdata($id);

            // Get the permalink to the original post on the original blog
            $permalink = network_get_permalink();

            // Get the post title
            $the_title = network_get_the_title();

            // Echo some information and a link
            echo "<a href='" . $permalink . "'>" . $the_title . " by " . $author->user_nicename . "</a>";
        }
    }
?>