To get a post from a specific category to appear at the top of the page above the rest of the posts, and to only change when a new post from that particular category is added, use the following code:

<?php /*?><?php $my_query = new WP_Query('category_name=featured&showposts=1');

while ($my_query->have_posts()) : $my_query->the_post();

$do_not_duplicate = $post->ID;?>

<div class="featureItem">

<h1>Feature: <a href="<?php the_permalink() ?>" rel="bookmark"><?php the_title(); ?></a></h1>
<p><?php the_time('F j, Y'); ?> • By <?php the_author_firstname(); ?> <?php the_author_lastname(); ?><br />Tags: <?php STP_PostTags(); ?> | <?php comments_popup_link('Leave a Comment', '1 Comment', '% Comments'); ?></p>
<?php the_content('Read more»'); ?>


<?php trackback_rdf(); ?>



<?php endwhile; ?>

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

continue;?><?php */?>

Obviously, many things above can be changed, like how the titles, categories, tags, etc. are displayed.