+1 that stuff works, but the best medicine is jsut being prepared and having confidence in your equipment. If my engine is tuned and my car is working top notch them I am always cooler and much more prepared. Another thing I like to do is to drive the track a few times and then walk the track paying special attention to where I am having problems. The track can look completely different from the drivers stand than when you are on the ground walking it. Show up to open practice the day before and get your car dialed in setup, tires, engine tuning etc. The best way to calm the nerves is to be prepared and find confidence in it. If all else fails take a deep breath and pray.