Efficiency question

I have googled around a bit, but not really found anything useful... Which is more efficient? A case switch or a $$method style method? An example: switch($action) { case 'edit': //do some stuff ....... return "edit_tpl.php"; case 'whatever': //blah ...... ...... } OR: $method=$this->convertToMethod($action); unset($action); return $this->$method(); Hope this is reasonably clear... Note the return on the latter code. If anyone has any ideas around this, please let me know! Are there underlying security risks in doing it this way? --Paul