Well, I mean a class that allows me to change the template of the website with a click from a menu, like on this forum.. you can quite easially change the theme from this theme to another(ofcourse you have to import it etc etc.. but you get the point).

And make a management system, like in vB edit template feature in the admin cp, where you can change the template code quite easially.

And they're using both php and html in the same document without any tags(don't quite understand how..), they write stuff like:
if($condition['show'] == 'member')
<a href="something.php">Forum index</a>


And that's how I would want it! To easially be able to CHANGE the templates imported, via an admin cp.

So, that's my pro/elite/1337 template class idea! :)
(hard - yes, impossible - noo :D)