Get IP Address

function getIpAddress() {
	// based on
	// http://stackoverflow.com/questions/527638/getting-the-client-ip-address-remote-addr-http-x-forwarded-for-what-else-could
	// http://www.grantburton.com/?p=97
	$check = array(
		'HTTP_CLIENT_IP','HTTP_X_FORWARDED_FOR','HTTP_X_FORWARDED',
		'HTTP_X_CLUSTER_CLIENT_IP','HTTP_FORWARDED_FOR','HTTP_FORWARDED','REMOTE_ADDR',
	);
	$ip = '0.0.0.0';
	foreach ($check as $key) {
		if (isset($_SERVER[$key])) {
			list ($ip) = explode(',', $_SERVER[$key]);
			break;
		}
	}
	return $ip;
}