Function to strip articles from slug. Slug can then be used to alphabetize post listings.

gistfile1.php

/**
 * strip_articles_from_slug
 *
 * Remove a, an, the from post slugs on new posts, so post listings 
 * can be alphabetized by slug and ignore leading articles
 *
 * @param $postarr post being set up
 * @param $data data for the database
 * @return array
 * @author Jessica Yazbek
**/
function strip_articles_from_slug($data, $postarr)
{
	if ( ! $postarr['post_name']) // new post without slug specified
	{
		$data['post_name'] = str_replace(array('~~~the-', '~~~a-', '~~~an-', '~~~'), array('', '', '', ''), '~~~'.$data['post_name']);
	}
	return $data;
}
add_filter('wp_insert_post_data', 'strip_articles_from_slug', 10, 2);