Is your screen clipping some highlights or shadows, so other people might see photoshop mistakes in your photos that you simply can't see on your screen? If you adjust the contrast and brightness of your screen the right way, this won't happen. And if you are shooting catalog photos and need calibrated screen images and prints at your fingertips, then go nuts and get yourself a calibration device.

The calibration wallpaper is here: http://ProPortfolioClub.com/wallpaper

The Spyder I use for color calibration: http://goo.gl/56JWTd

Photo: Do you see the white perls in the white veil on the white background?