How to show video from specific category on sidebar?

If you’re video embeds are always the same, I like the solution proposed by 5wpthemes, but if you want to avoid having to use a custom field ( and more specifically, remembering to do it), you could also try the code below ( which also requires the code to be very similar in every post ).

<?php $my_query = new WP query(array('cat'=>6, 'showposts'=> '2')); ?>
<?php while ($my_query->have_posts()) : $my_query->the_post(); ?>
    $theContent = get_the_content();
    $parts = explode("iframe",$theContent);
    ?><iframe<? echo $parts[1]; ?>iframe><?php
<?php endwhile; ?>