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]