Get Customer Shipping/Billing Address

$customerAddressId = Mage::getSingleton('customer/session')->getCustomer()->getDefaultShipping();
if ($customerAddressId){
       $address = Mage::getModel('customer/address')->load($customerAddressId);
}
else
{
 $address = Mage::getSingleton('checkout/session')->getQuote()->getShippingAddress();
}