Excellent! Works well for the title tag too. I use it now like this:
<article <?php post_class() ?> id="post-<?php the_ID(); ?>">
<div class="entry"><div class="postmain">
<?php
$alt = get_post_meta( get_post_thumbnail_id($post->ID), '_wp_attachment_image_alt', true );
$src = wp_get_attachment_image_src( get_post_thumbnail_id($post->ID), '', false, '' ); $thumbnailSrc = $src[0]; ?>
<a href="<?php echo $thumbnailSrc;?>" title="<?php echo $alt; ?>"><img class="ethumb" src="<?php bloginfo('template_directory'); ?>/timthumb.php?src=<?php echo $thumbnailSrc;?>&h=149&w=149&zc=1" alt="<?php echo $alt; ?>"/></a>
</div></div>
</article>
Thanks for thinking with me!
Btw, for other people, this code combines Featured Image with timthumb.php. Featured Images will be automatically scaled to fit.