The easiest and most clean way to solve that problem is using a specialised object.
First create a class that can hold extra information:
class Menu_Page
{
public $extra="";
public function render()
{
print $this->extra;
}
}
Now create an object from that class …
$page = new Menu_Page;
$page->extra="Hello World!";
… and register its method render()
as callback:
add_users_page(
'Test',
'Test',
'manage_options',
'test',
array( $page, 'render' )
);