I'm not sure if The Avenger—this elaborate Xbox controller exoskeleton—will improve your performance markedly. But my goodness, it'll make you look prepared. Or, you know, like your controller has polio.
A Microsoft patent shows off a new dual-mode Xbox 360 controller that can be used both wired and wirelessly. Unlike the current play and charge kit, this controller would give you the accuracy of a true wired mode when plugged in.