Add a tab to the WooCommerce product page

// WooCommerce 1.6 has no tabs filter: a tab is two actions.
add_action('woocommerce_product_tabs', 'shop_care_tab', 25);
add_action('woocommerce_product_tab_panels', 'shop_care_panel', 25);

function shop_care_tab() {
    echo '<li class="care_tab"><a href="#tab-care">Care</a></li>';
}
function shop_care_panel() {
    echo '<div class="panel" id="tab-care">' . wpautop(get_post_meta(get_the_ID(), '_care_instructions', true)) . '</div>';
}