The Coding Horror blog has written up "Computer Display Calibration 101".
"If you've invested in a quality monitor for your computer, you owe it to yourself— and your eyes— to spend 15 minutes setting it up properly for your viewing environment."
It also points out that Microsoft Media Center has a decent display calibration wizard built in. That I did not know.
Unfortunately since the DVI input on my monitor went south for no reason that I can discern, I'm back in VGA hell, but reading this post has given me a boot up the bum to actually get that fixed.
Computer Display Calibration 101 [Coding Horror]