Electro Harmonix for a long time has been guitarist's tools of choice for the effect afficiondo. Recently the y have released a new vocal oriented pedal that is a vocoder. Essentially a smaller version of their V256 band vocoder pedal. It also features gender bender knob to go from male to female and somewhere in between. To my ears this is a rock solid unit when you are going for this type of effect. Vist and learn more about the Iron Lung here.