get gravatar url

/*
    - Get Gravatar URL
    - Get the URL for a gravatar attached to someone's email address to be used
      in the <img> tag.

    $email     - The email to fetch the gravatar of.
    $size      - The size of the gravatar to be fetched (default 40 pixels)
    */

    public function getGravatarURL($email, $size = 40) {
        $email = md5(trim($email));
        $grav_url = "http://www.gravatar.com/avatar/" . $email . "?s=" . $size;
        return $grav_url;
    }