How can I disable PHP magic quotes at runtime?

I'm writing a set of PHP scripts that'll be run in some different setups, some of them shared hosting with magic quotes on (the horror). Without the ability to control PHP or Apache configuration, can I do anything in my scripts to disable PHP quotes at runtime?

It'd be better if the code didn't assume magic quotes are on, so that I can use the same scripts on different hosts that might or might not have magic quotes.

Only magic_quoted_runtime can be disabled at runtime. But magic_quotes_gpc can’t be disabled at runtime (PHP_INI_ALL changable until PHP 4.2.3, since then PHP_INI_PERDIR); you can only remove them:

if (get_magic_quotes_gpc()) {
    $process = array(&$_GET, &$_POST, &$_COOKIE, &$_REQUEST);
    while (list($key, $val) = each($process)) {
        foreach ($val as $k => $v) {
            unset($process[$key][$k]);
            if (is_array($v)) {
                $process[$key][stripslashes($k)] = $v;
                $process[] = &$process[$key][stripslashes($k)];
            } else {
                $process[$key][stripslashes($k)] = stripslashes($v);
            }
        }
    }
    unset($process);
}

For further information see Disabling Magic Quotes.