Here is my set up, used a ‘BUD sandwich raspberry pi box’ with little modification to flip the RPi around so a 7 port USB powered hub can be added to the lower section, the HUB is from DX.com, the power conector was kinda lose so it was removed power lines soldered directly with a added switch for easy on/off. Added wireless Xbox controllers with a converted RF module from a dead 360.
Here are some more pics of my setup. Added a Fan now to the case
The Xbox360 RF module is a fairly simple hack for just controller support but extra hardware is needed to enable sync function as I have done.
The Fan came from an old video card, I liked the way it looked on top of the case.
Still on the to do list is to add an RTC (real time clock)DS1307 to the RPi so every thing can be a little more portable or dose not need net connection every time.