This Instructable is a stand-alone, as well as a companion to another Instructable that i have to do an easy Softmod to your Original XBox without needing a Memory Card or Action Replay. Keep in mind that the Memory Card made by Microsoft is a FAT16 Device, but has 8 Megabyte Limitations. After doing this to my XBox controller, i was able to easily use a Kingston DataTraveller 4 Gigabyte USB stick with ease. This is also handy when you are limited to One Controller/Breakaway combo, like i am, and need to be able to transfer your files and interface at the same time with the XBox.
Credit for the Pinout diagram goes to Mike Chambers (who made a Memory Card to USB Adapter, but i simply cut out the middleman and hardwired the USB port directly into the controller!) his project can be seen at: http://mesh.typepad.com/blog/2005/01/creating_a_usb_.html
Another helpful resource for anyone undertaking any project using USB will appreciate this site:http://pinouts.ru/Slots/USB_pinout.shtml
This site gives some good visual guides on most things USB (even lists iPod and other proprietary connectors).