Getting the grand total from Magento shopping cart

Getting the grand total, the final checkout price after all discounts and taxes are applied.

$quote = Mage::getModel('checkout/session')->getQuote();
$quoteData= $quote->getData();
$grandTotal=$quoteData['grand_total'];

Caculating the grand total without the promotion rules.

$quote = Mage::getModel('checkout/session')->getQuote();
$grandTotal = 0;
foreach ($quote->getAllItems() as $item) {
 $grandTotal += $item->getPriceInclTax()*$item->getQty();
}

This code will show all available shopping cart related values.

$quote = Mage::getModel('checkout/session')->getQuote();
print_r($quote->getData());

Note: Shipping cost are not included in the above grand totals.