You guys are missing the boat here - It isn't a couple parts and BOOM! you have a USB device. USB is WAY more complex than that. You notice in the picture that big black thing - it is a microcontroller, most likely a PIC16C765. What you are paying for from this guy, and others, is the code that communicates between the controller and the computer. To use USB, you need to have support that sends information, such as what type of device is being used, what information will be sent, what to do with information that is recieved, etc.
His devices are cool, but not that complex.
That Black Chopper site is neat, but also overpriced. 15 dollars per cord is quite a bit.
Anyway, everyone has ignored/forgotten Hemphacker's and my project. I also offered up the idea of a console converter -> keyboard encoder, but there was zero interest.
I just find it suprising that people want to pay 50 bucks to use only two controllers.