Description:
------------
At the moment there is no reliable way to determine whether a function is being 
called statically or on an object directly. Sometimes it's useful to know the 
difference between e.g.
foo::createUrl();
and
$foo->createUrl();

it would be nice to have a function, called something like is_static_call() which 
could supply this information to the current method. I'm not familiar with the PHP 
internals so I don't know how difficult this is to implement, but for me it would 
be a useful feature.

Test script:
---------------
class foo {
	public function createUrl($url = null, $params = array()) {
		if ($url === null && is_static_call()) {
			$url = "list";
		}
		elseif ($url === null) {
			$url = "view";
		}
		/* do something */
	}
}