iPhone & iPod Detection Using JavaScript or PHP

I was browsing the ESPN.com source code recently and stumbled upon their method of detecting iPhone / iPod touch users and redirecting them to their iPhone-compatible website.

The JavaScript

if((navigator.userAgent.match(/iPhone/i)) || (navigator.userAgent.match(/iPod/i))) {

   if (document.cookie.indexOf("iphone_redirect=false") == -1) window.location = "http://m.espn.go.com/wireless/?iphone&i=COMR";

}

The code itself is short and sweet. I, however, would prefer using the server-side method of user agent checking.

The PHP

if(strstr($_SERVER['HTTP_USER_AGENT'],'iPhone') || strstr($_SERVER['HTTP_USER_AGENT'],'iPod'))

{

  header('Location: http://yoursite.com/iphone');

  exit();

}