When a method is called that doesn't explicitally exist within an object, PHP5 will now call the special method __call() method

<?php
    class dyn_class {

        function __call($f_name, $args) {

            echo "You called $f_name, # of params: ".count($args);
        }
    }

    $test = new dyn_class();
    $test->call_my_function();
    $test->call_another_function(20);
?>