Alt+choose Image> Duplicate
:: menu commands :: :: navigation :: :: painting and editing :: :: type :: :: applying colors :: :: selections :: :: layers :: :: blend and brush modes :: :: channels and masks :: :: path :: :: crops and transformations :: :: rulers, measur. & guides :: :: advanced color corrections :: :: filters :: :: misc ::
All of the commands are taken from Photoshop Bible 6 and its' author Deke McClelland