Sameer Borate has posted about an alternative templating system that's currently being used in multiple languages - Haml (HTML Abstraction Markup Language). As Sameer points out, there's also a PHP port of it.

It has been a while since I’ve used a template engine during development, the last one I used was Smarty. Now there are a plethora of template systems, but most are a rehash of Smarty. Readers may beg to differ, but Smarty gets the work done, which is all that matters. The one that I found really interesting is Haml.

He includes some markup examples of how it's structured - the main structure of the site, tables, divs, etc - and what it comes out like on the other side of the parser. The phphaml and phamlp libraries let you run the template through with variable values set and display it. There are some downsides he mentions, though, like the rules on indentation and that the markup has to be all in one file (or combined before sending to be rendered).