WordPress Custom Query

<?php

 $querystr = "
    SELECT wposts.* 
    FROM $wpdb->posts wposts, $wpdb->postmeta wpostmeta
    WHERE wposts.ID = wpostmeta.post_id 
    AND wpostmeta.meta_key = 'date_field' 
    AND wpostmeta.meta_value="03/11/2010" 
    AND wposts.post_status="publish" 
    AND wposts.post_type="post" 
    ORDER BY wposts.post_date DESC
 ";

 $pageposts = $wpdb->get_results($querystr, OBJECT);

 ?>

Then you would access $pageposts as an object