As Phil said I changed my gear knob to the carbon/chrome Nismo one whilst I was up at ESR and to me it's made sooooo much difference to the way that the car drives it's unreal. The shifts feel 10x more precise and smoother, and also the throw feels shorter. The stock gear knob is like the broken link in the transmission, and as strange as it sounds you feel more "connected" to the gearbox and the changes with one of these. Switch over to any one of the gear knobs Phil has in stock and I guarantee you'll be impressed with the difference it makes, the stock one is crap!
(also, they vibrate a hell of a lot less than the stock one for some reason. )