Exluding posts from new WP_Query

Hey all!
Hope all is ok.
I have a news page that I am setting up.
I currently have a query that shows posts only from a particular category. This is my code:

<?php $recent = new WP_Query("cat=8&showposts=1"); while($recent->have_posts()) : $recent->the_post();?>

What I want to do now is set up another query that will show all posts EXCEPT for categories 8 and 9. How do I construct the query to show all posts except cat 8 and 9?

Really hope someone can help.

Regards,
David