A better way of adjusting saturation. This technique adjusts saturation according to the level of saturation in the image.
Open a photo you would like to edit. Or, you may use the photo used in this tutorial (from iStockPhoto).

Create a new Hue/Saturation adjustment layer (Layer> New Adjustment Layer> Hue/Saturation). When the Hue/Saturation tool appears, reduce the saturation to -100. Click OK when done.

Change the blending mode of the adjustment layer to Difference.
