I need a catagory post displayer plugin

<?php
$catquery = new WP_Query( 'cat=3&posts_per_page=10' );
while($catquery->have_posts()) : $catquery->the_post();
?>
<ul>
<li><h3><a href="<?php the_permalink() ?>" rel="bookmark"><?php the_title(); ?></a></h3>

<ul><li><?php the_content(); ?></li>
</ul>
</li>
</ul>
<?php endwhile; ?>

At the top where it says showpost= change the number to how many posts you want to display, and cat=3 is the id of the category, so change the ID of the category to pick which category will you be displaying.