Here is how to build a set of timezone clocks using PHP, jQuery and CSS3. It's based heavily on Toby Pitman's example, and even uses his images.
I've added the extra timezones using a PHP array. In theory it would be possible to do it all in Javascript, but PHP is good at handling dates, and there's no need to do any horrible maths with timezone offsets. Just tell the server which timezone you are interested in.
