clarification of module functionality

Basic functionality of this module is APIs to convert ip to country. If you want to redirect according to IP, you need to write a short php snippet.

I do it in a custom module like this:

/**
 * Implementation of hook_init().
 */
function mymodule_init() {
  global $language;
  global $base_url;
  
  if ($_SERVER['SCRIPT_NAME'] != $GLOBALS['base_path'] .'index.php') return FALSE;

  /**
   * If the site is in offline mode there is little point doing any of this as you might end up redirecting to a 503.
   */
  if (variable_get('site_offline', 0) == 1) return FALSE;

  /**
   * We only want to act if the user comes to the page from an external site/direct hit
   */
  if (strpos($_SERVER['HTTP_REFERER'], $_SERVER['SERVER_NAME'])) return FALSE;
  
  /**
   * If ip2cc code is not installed then we bail
   */
  if (!module_exists('ip2cc')) return FALSE;
  
  // only run this for the homepage
  if (drupal_is_front_page()) {
    // Get the Query String (minus the 'q'). If none set, set to NULL
    $query_string = drupal_query_string_encode($_GET, array('q'));
    if (empty($query_string)) {
      $query_string = NULL;
    }

    // Establish the language prefix that should be used, ie. the one that drupal_goto() would use
    $options = array('prefix' => '');
    if (function_exists('language_url_rewrite')) {
      // Note that language_url_rewrite() takes path (by reference) as the first argument but does not use it at all
      $path = $_REQUEST['q'];
      language_url_rewrite($path, $options);
    }
    $prefix = rtrim($options['prefix'], '/');
    
    // Establish the users country
    $ip2cc = ip2cc_get_country(ip2cc_get_user_ip_address());
    $cc = strtolower($ip2cc->country_code);

    // redirect uk users to the UK site
    if ($cc == 'gb') $cc = 'en';
    if (!$cc) return FALSE;
    
    // redirect the user to a language specific version if
    // 1. the country code maps to an enabled language
    // 2. the country code is not the active language
    // 3. the user has not asked for a specivic version
    $languages = language_list('enabled');
    foreach ($languages[1] as $lang) {
      if ($lang->language == $cc && $language->language != $cc && !$prefix) {
        drupal_goto($base_url .'/'. $cc .'/node', $query_string, NULL, 303);
        return;
      }
    }
  }
}

If your still looking for a solution to redirect users based on IP address, I have just developed the IP2Locale module:

http://drupal.org/project/ip2locale