Is it possible to curry method calls in PHP?

I have a SoapClient instance generated for a WSDL file. All except one of the method invocations require the username and the password to be passed id.

Is there any way of currying the method calls so that I can omit the username and password?

As of php 5.3 you can store an anonymous function in a variable. This anonymous function can call the "original" function with some predefined parameters.

function foo($x, $y, $z) {
  echo "$x - $y - $z";
}

$bar = function($z) {
  foo('A', 'B', $z);
};

$bar('C');

edit: You can also use a closure to parametrise the creation of the anonymous function

function foo($x, $y, $z) {
  echo "$x - $y - $z";
}

function fnFoo($x, $y) {
  return function($z) use($x,$y) {
    foo($x, $y, $z);
  };
}

$bar = fnFoo('A', 'B');
$bar('C');

edit2: This also works with objects

class Foo {
  public function bar($x, $y, $z) {
    echo "$x - $y - $z";
  }
}

function fnFoobar($obj, $x, $z) {
  return function ($y) use ($obj,$x,$z) {
    $obj->bar($x, $y, $z);
  };
}

$foo = new Foo;
$bar = fnFoobar($foo, 'A', 'C');
$bar('B');

But the other suggestions using __call() and a wrapper class may be better if you want to "enhance" a complete class.