Detección de navegador en PHP, Javascript y HTACCESS

Códigos en JavaScript, PHP y .htaccess para detectar el dispositivo/navegador del cliente que realiza la petición para poder actuar en consecuencia.
Código JAVASCRIPT
// android
var ua = navigator.userAgent.toLowerCase();
var isAndroid = ua.indexOf("android") > -1; //&& ua.indexOf("mobile");
if(isAndroid) {
// Do something!
// Redirect to Android-site?
window.location = 'http://android.yourdomain.com';
}

// ipad
// For use within normal web clients
var isiPad = navigator.userAgent.match(/iPad/i) != null;

// For use within iPad developer UIWebView
// Thanks to Andrew Hedges!
var ua = navigator.userAgent;
var isiPad = /iPad/i.test(ua) || /iPhone OS 3_1_2/i.test(ua) || /iPhone OS 3_2_2/i.test(ua);

// iphone/ipod
if((navigator.userAgent.match(/iPhone/i)) || (navigator.userAgent.match(/iPod/i))) {
if (document.cookie.indexOf("iphone_redirect=false") == -1) window.location = "http://yoursite.com/iphone";
}

Código PHP
// android
$ua = strtolower($_SERVER['HTTP_USER_AGENT']);
if(stripos($ua,'android') !== false) { // && stripos($ua,'mobile') !== false) {
header('Location: http://android.yourdomain.com');
exit();
}

// ipad
$isiPad = (bool) strpos($_SERVER['HTTP_USER_AGENT'],'iPad');

// iphone/ipod
if(strstr($_SERVER['HTTP_USER_AGENT'],'iPhone') || strstr($_SERVER['HTTP_USER_AGENT'],'iPod'))
{
header('Location: http://yoursite.com/iphone');
exit();
}

Código HTACCESS
// android
RewriteCond %{HTTP_USER_AGENT} ^.*Android.*$
RewriteRule ^(.*)$ http://android.yourdomain.com [R=301]

// ipad
RewriteCond %{HTTP_USER_AGENT} ^.*iPad.*$
RewriteRule ^(.*)$ http://ipad.yourdomain.com [R=301]

// iphone/ipod
RewriteEngine on
RewriteCond ${HTTP_USER_AGENT} iPhone
RewriteRule .* http://yoursite.com/iphone