Latest post in full, older posts in excerpt

I’m trying to get the latest post to display in full on the front page, then the earlier posts as excerpts. On the older pages (blog.com/2/ using older/newer navigation), I want jsut the list of excerpts. The code below works great, but continues to display the latest post in full on the older pages. I’ve tried som if/then statements to only make it display on the frontpage, but can’t quite make it work. Any suggestions?

Thanks!

Setting up the latest post to display in full:

<?php $my_query = new WP_Query('showposts=1');
while ($my_query->have_posts()) : $my_query->the_post();
$do_not_duplicate = $post->ID; ?>

Div for ONLY the latest post:

<div id="post-<?php the_ID(); ?>" <?php post_class(); ?>>
CONTENT
</div>

<?php endwhile; ?>

Now my Loop showing only older posts:

<?php if (have_posts()) : while (have_posts()) : the_post();
if( $post->ID == $do_not_duplicate ) continue; update_post_caches($posts); ?>

<div id="post-<?php the_ID(); ?>" <?php post_class(); ?>>
CONTENT
</div>
<?php endwhile; endif; ?>