Mage::getModel('sales/order')->load($orderId)->getAllItems();
Total items added in cart
Mage::getModel('checkout/cart')->getQuote()->getItemsCount(); Mage::getSingleton('checkout/session')->getQuote()->getItemsCount();
Total quantity added in cart
Mage::getModel('checkout/cart')->getQuote()->getItemsQty(); Mage::getSingleton('checkout/session')->getQuote()->getItemsQty();