How to customize Meta Tags

Hi, I have managed to customize my meta description and title tags, by using <?php bloginfo('name'); ?> and <?php bloginfo('description'); ?> to my satisfaction, however I am trying to set up my Meta Keywords tag so that the posts tags, appear as keywords, I tried using the <?php the_tags('Tags: ', ', ', '<br />'); ?> however it seems this doesnt pass anything when the page generates and i also notice this generates the links, is there any piece of code i can just put into my meta tag to generate the tags when im on a single page?

thanks in advance, hope that makes sense…