yeah, the controller is actually just a 3 port USB hub (2 memory card interfaces and the actual controller itself on the 3rd.)
i have a cable I cut off and wired a usb onto it. when softmodding, i just plug it into one of the other ports. I actually used a male usb and use a F-F adapter to plug the USB onto it. That way I could use the controller on my computer.
alternatively, you can do above and mod a memory unit with a usb and plug it into a controller and not hack up one of your controllers cords. The memory units are stupid and useless anyways since most people just save games to the hard drive and don't really take their saves to friends houses.