/**
     * Returns a list of the replies sent to the authenticating user.
     * @param string $since (HTTP-formatted date) Optional.  Narrows the resulting 
     * list of direct messages to just those sent after the specified date. 
     * @return string
     */
    function replies( $since = false )
    {
        $qs='';
        if ( $since !== false)
            $qs = '?since_id=' . urlencode($since);
        $request = 'http://twitter.com/statuses/replies.' . $this->type .$qs;
        $out = $this->process($request);
        return $this->objectify( $this->process($request) );
    }