heres a small snippet, just an example how its done, but you would need to build a db of sites that it would parse.
and of course change published to future
PHP Code:
<?php
$how_many=15; //how many posts to display
require('blog1/wp-config.php'); //the path to the wp-config file of the blog I want to use
$news=$wpdb->get_results("SELECT 'ID','post_title','post_content' FROM $wpdb->posts WHERE 'post_type'=\"post\" AND 'post_status'=\"publish\" ORDER BY post_date DESC LIMIT $how_many");
foreach($news as $np){
printf ("<div class='normalText'>%s</div>", $np->post_content);
}
?>