radio shack
5v voltage regulator chip
follow the wireing directions on the back of the package. its got 3 pins on it. incoming power (9v in your case), outgoing power @ 5v and ground. piece of cake.
that is already taken care of in the VR box. If its output you need, and just a cable....then hack a usb cable. there are 4 wires. two are for power, two are for data. you only need worry about the two for power. its easy to google up that info. Just have to know what to look for. In this case, its "USB cable pin out" and you'll find everything you need to know.