Hi bebs,
Somewhere In Acamas' functions.php you'll need to add this line:
add_theme_support( 'post-thumbnails', array( 'post' ) );
Then search for <div id="feature-content">
and change
<div id="feature-content">
<?php the_excerpt(''.__('Read More <span class="meta-nav">»</span>', 'thematic').'') ?>
To:
<div id="feature-content">
<?php if ( has_post_thumbnail() ) {
the_post_thumbnail();
} else {
// the current post lacks a thumbnail
// So add your default Thumbnail Image or fallback code here
}?>
<?php the_excerpt(''.__('Read More <span class="meta-nav">»</span>', 'thematic').'') ?>
You'll need to read up on the new post thumbnail feature in WordPress to unlock more of it's secrets so look here:
http://justintadlock.com/archives/2009/11/16/everything-you-need-to-know-about-wordpress-2-9s-post-image-feature
http://markjaquith.wordpress.com/2009/12/23/new-in-wordpress-2-9-post-thumbnail-images/
-Gene