Load Product by ID or SKU or Name

//Load by ID
$ID=1; //ID of the product
$_product = Mage::getModel('catalog/product')->load($ID);  

// Load by SKU  
$_product = Mage::getModel('catalog/product')->loadByAttribute('sku', 'myproduct'); 

// Load by Name
$_product = Mage::getModel('catalog/product')->loadByAttribute('name', 'my product');