adding a site-wide rss feed...

I've cobbled together a site-wide RSS feed, adding it to summary.module. Seems to work except I get a "warning: Cannot modify header information - headers already sent by" message before the RSS feed. Any thoughts?

All I did was modify summary.module to add an item in summary_menu():

	$items[] = array ('path' => 'summary/feed', 'title' => t('summary feed'), 'access' => TRUE, 'callback' => 'summary_feed', 'type' => MENU_CALLBACK);

and then added this function:

function summary_feed() {
    if (user_access("access content")) {
        $types = node_list();
        foreach ($types as $type) {
            if (variable_get("summary_show_".$type, 0)) {
                $result = summary_get_nodes($type, variable_get("summary_".$type, 0));
                node_feed($result);
            }
        }
    }
}

( know this won't quite yet work right, because the node_feed() call is in the wrong place, but it's close)

Any thoughts? Thanks...