How can I redirect iPhone users to a mobile version of a website?

So I’ve (sort of) managed to create a mobile-version of a friends’ website using Dashcode. I was just wondering if there was a simple way to detect users browsing with Mobile Safari and redirect them to the mobile version of the website. I found this page (http://www.knoxing.com/2008/08/04/iphone-seo/) but as far as I can see the ‘updated script’ is not ‘below’. Damn. Any help is much appreciated.