I\'m not talking about inheritance. And I\'m not talking about nested objects. I\'m talking:
System::Web::Templating(...)
kind of
No.
However, you could do something like this by returning an instantiated object in getInstance():
myClass::getInstance()->foo();
nope, you can’t nest classes in php. see: http://bytes.com/topic/php/answers/10138-nested-classes-php
It seems that you're speaking about namespaces, not about any kind of nesting. This feature was implemented in PHP 5.3, and is documented here.