gistfile1.txt

    protected function _initCategories()
    {
        $collection = Mage::getResourceModel('catalog/category_collection')->addNameToResult();
        /* @var $collection Mage_Catalog_Model_Resource_Eav_Mysql4_Category_Collection */
        foreach ($collection as $category) {
            $structure = preg_split('#/+#', $category->getPath());
            $pathSize  = count($structure);
            if ($pathSize > 1) {
                $path = array();
                for ($i = 1; $i < $pathSize; $i++) {
                    $path[] = $collection->getItemById($structure[$i])->getName();
                }
                $this->_rootCategories[$category->getId()] = array_shift($path);
                if ($pathSize > 2) {
                    $this->_categories[$category->getId()] = implode('/', $path);
                }
            }

        }
        return $this;
    }