Communicating with a GameCube controller?

So a while ago I posted asking about how I might get some wireless control working with my Arduino, for cheap. I didn't want to bump that thread, but anyways I decided on 2 methods. The first one which I have already implemented with my Sumo Bot, is IR signals. I did that with the help of the IRreciever library. That works great but I still want to go with something with a more "analog" feel. So I read about interfacing with a Wii Nunchuck via a library using wire to communicate through the I2C bus. I also learned that the Nunchuck has the same pin-out as a GameCube controller. I remembered that I had my Wavebird which would be the perfect RF solution with plenty of buttons to push and two analog sticks. I've scoured the internet for a simple way to use a GC controller but have not found an answer.

My main questions are:

  1. How can I communicate with a GameCube controller? (just hoping someone's got a simple answer)

  2. Does the Gamecube use serial communication or I2C?

  3. Are serial and I2C the same thing? and can anyone explain the difference?

Thanks in advanced!