Magento Load Product By Name / SKU / ID

// Load by name
$_category = Mage::getModel('catalog/category')->loadByAttribute('name', 'Ruby Ring');
$_product = Mage::getModel('catalog/product')->loadByAttribute('name', 'emerald earring');

// Load by SKU
$_product = Mage::getModel('catalog/product')->loadByAttribute('sku', 'Eram18j4');

//Load by ID (just load):
$_product = Mage::getModel('catalog/product')->load($productID);