For instance, if you want to use a string as part of a URL but need to make it safe for that kind of use.

function replaceAccents($str) {
    $str = htmlentities($str, ENT_COMPAT, "UTF-8");
    $str = preg_replace('/&([a-zA-Z])(uml|acute|grave|circ|tilde);/','$1',$str);

    return html_entity_decode($str);
}