How to hide post title and date based on category.

Hi,
I’m not that familiar with PHP, but basically what I want to do is hide my post title and date/metadata if it’s in my asides category (category number is 9). Here’s the code from my template:

<div class="post" id="post-<?php the_ID(); ?>">
<h2><a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title(); ?>"><?php the_title(); ?></a></h2>
<p id="date"><?php the_time('F jS, Y') ?> <!-- by <?php the_author() ?> --></p>

<div class="entry">
<?php the_content('Read the rest of this entry &raquo;'); ?>
</div>
<p class="postmetadata">Posted in <?php the_category(', ') ?> <strong>|</strong> <?php edit_post_link('Edit','',' <strong>|</strong>'); ?> <span class="metadatacomments"><?php comments_popup_link('No Comments »', '1 Comment »', '% Comments »'); ?></span></p>
</div>

I know there’s an in_category tag, I didn’t know if there was something like is not category. Any help would be most appreciated!