Magento: How to tell if you're on a category page, or product page in .phtml file(s)

Question

I am trying to program into my .phtml files an if statement if the guest is on a category list page, or on a product page.

For example this code:

Answer 1

I am not a big fan of checking if the current_category registry exists, because basically any controller could do this and it wouldn't necessarily mean it's a category. My way of doing it is a bit more robust:

$fullActionName = Mage::app()->getFrontController()->getAction()->getFullActionName();
if ($fullActionName == 'catalog_category_view') { 
    ...  //Category
}
elseif ($fullActionName == 'catalog_product_view') {
    ...  //Product
}