here is an example loop..
you can change the number of tag to exclude based on the amount you want…
<?php
if (have_posts()) : while (have_posts()) : the_post();
// GET THE TAGS OF CURRENT POST IN LOOP AND COUNT THE AMOUNT
$posttags = get_the_tags();
$howmany = count($posttags);
if($howmany > 2) {
?>
<h3><?php the_title(); ?></h3>
<?php the_excerpt(); ?>
<?php
} else {
// do nothing
}
endwhile;
?>
<?php endif; ?>
.
Hope This Helps
Sagive