magento get last added item from session or get cart items from session

How to get all cart items from cart session in magento

$productid=Mage::getSingleton('checkout/session')->getLastAddedProductId(true);

-----------OR----------------------------
$session= Mage::getSingleton('checkout/session');
foreach($session->getQuote()->getAllItems() as $item)
{
$productid = $item->getProductId();
$productsku = $item->getSku();
$productname = $item->getName();
$productqty = $item->getQty();
}