show all products button(text in dropdown) in product sorting option in magento

add the following code into toolbar.phtml

<a href="<?php echo $this->getLimitUrl('all') ?>"><?php echo $this->__('View All') ?></a>

and then add following code to toolbar.php block file

public function getLimitUrl($limit)
    {
        return $this->getPagerUrl(array(
            $this->getLimitVarName() => $limit,
            $this->getPageVarName() => null
        ));
    }

and then make some changes in Backend configuration catalog section.

Configuration > catalog > frontend > Allow All Products per Page > yes ;)

Done!

Thanks!