Query based on whether posts have a featured image

Ever need to query for posts based whether they have a post thumbnail? This can be accomplished by adding 'meta_key' => '_thumbnail_id' to the query args:

[php] <?php $args = array( 'posts_per_page' => 1, 'meta_key' => '_thumbnail_id' ); $my_query = new WP_Query( $args );

if ( $my_query->have_posts() ) : while ( $my_query->have_posts() ) : $my_query->the_post(); ... [/php]