OK, for 5.5 and below Dodger's technique is the better technique, and he makes a good point. My technique does change the entire spectrum. There is one other feature, which cancels this out and adds the Gradient Map as a more subtle effect, or more pronounced depending on how you use it. They're called Adjustment Layers and they can be accessed either by using the little button on the layer palette that looks like a half-moon (it's a pop-up menu), or through the Layer menu, under the Add>/Add Adjustment>/whatever submenu happens to have them (they appear in several areas, increasingly so in later versions...7 makes them available in five locations). Anyway, applying the Gradient map in this fashion opens the possibility of bledning modes and opacity settings being applied to the effect...plus the whole slew of layer effects and layer masks. This does, however, take more time and Dodger's technique is far and away the faster and simpler of the two. However, one of the inherent beuties of Photoshop is that there are usually 5 or 6 different ways to approach any problem, and none of them is neccessarily better than another.