Magento:: Product Collection using Ids Or Sku

Following code load product useing ids.

$productIds = array(5, 22, 45, 75, 88);
$attributes = Mage::getSingleton('catalog/config')->getProductAttributes();
$_productCOllection = Mage::getModel('catalog/product')
                ->getCollection()              
                ->addAttributeToFilter('entity_id', array('in' => $productIds))
                ->addAttributeToSelect($attributes);// $attributes or '*'

or collection within a range

$_productCOllection = Mage::getModel('catalog/product')->getCollection()
   ->addAttributeToSelect('*')
   ->addAttributeToFilter('entity_id', array(
    'from' => $startPrOID,
    'to' => $EndPrOID
    ))
    ->load();

Following code load product useing SKUs.

$productSku = array('1111', '1112', '1113', 'HTC Touch Diamond', 'microsoftnatural');
$attributes = Mage::getSingleton('catalog/config')->getProductAttributes();
$collection = Mage::getModel('catalog/product')
                ->getCollection()              
                ->addAttributeToFilter('sku', array('in' => $productSku))
                ->addAttributeToSelect($attributes);