Manipulating wordpress the_loop - merging a original query with external posts.

gistfile1.php

<?php

// Run original query, exclude category (in our case 4)
query_posts( "showposts=40&cat=-4");
$wp_query->get_posts(); // this will force the query to run
			
// Grab different data, in our case, data from our twitter category
$twitter = get_posts( "cat=4&showposts=3");
			
// Then we insert posts into $wp_query->posts using a loop and splice
$step = floor( count($wp_query->get_posts())/count($twitter) );
			
for( $i=0; $i<count($twitter); $i++ )
{
	array_splice( $wp_query->posts, $step*$i, 0, Array($twitter[$i]));
}

// And finally, we need to set a new length for the query			
$wp_query->post_count = count($wp_query->posts);

?>