You'd be surprised how close I've come to buying a colorimeter. To calibrate the grayscales properly on my projection television, you need one of them. I've been doing it by trial-and-error, and I think I've got a decent white balance and grayscale on my set, but it took a lot of futzing over a long period of time. Kind of like adjusting your EQ in the car, you have to make small tweaks and live with them for a while.