Get currency rates for a multiple currencies in magento

you can get currency rate by using below code :

Mage::getModel(directory/currency);

i have try for get currency rates for a multiple currencies in magento a site. First: get allowed currency for a store

$currencyModel = Mage::getModel(directory/currency);
$currencies = $currencyModel->getConfigAllowCurrencies();

  get base currency for a store

$baseCurrencyCode = Mage::app()->getStore()->getBaseCurrencyCode();
$defaultCurrencies = $currencyModel->getConfigBaseCurrencies();

  Then fetch currency code rate and complete code is  

$currencyModel = Mage::getModel('directory/currency');
$currencies = $currencyModel->getConfigAllowCurrencies();
$baseCurrencyCode = Mage::app()->getStore()->getBaseCurrencyCode();
$defaultCurrencies = $currencyModel->getConfigBaseCurrencies();

$rates=$currencyModel->getCurrencyRates($defaultCurrencies, $currencies);
foreach($rates[$baseCurrencyCode] as $key=>$value  ) {
echo $key."-";
echo $value;
echo "<br/>";
            }

    Displaying different currencies for a single product     If get different currencies for a product and want of product price difference rate then just multiply rate

$rate*$proPrice;

  Magento currency rates is manged from admin, so to admin > system >Manage Currency >Rates and managed currency symbol from admin > system >Manage Currency >Symbols If want to add multiple currency then goto admin > system > GENERAL > Currency setup> Allowed Currencies