Depends on how you want to use it. If you want to use it to shoot video from a plane, I solder the male end of a servo ext to the usb and a female end to the power on the camera side. Then I solder the opposite ends onto the USB cable. You can use the power lead on the camera with a standard RC battery connection or you can make a cable to plug directly into your receiver for power. This way you don't have to have several different wires to plug into your camera to power and download.

Go to the camera hacking site listed in this thread and take a look at their how to section. It has many explanations of how to make cables.

Patrick.