We've talked about other ways of converting to b/w but this one, to me, is probably the best, at least the most adjustable. When PS converts an rgb color photo to grayscale it takes the red, green and blue channels and mixes them in different proportions. These proportions are stored in software and are based on how the eye responds to color. We can do it the same way but allow us to control what percentage of each channel is used.
Open the image you want to convert. You should have the layers pallete open if not select Windows-->Layers or hit F7. Should have something like this 
Figure 1
In layer palette, select background layer and hit <Ctrl-J> to copy current layer to new layer, or drag background layer to new layer icon at bottom of layer palette. Figure 2 You can bypass this step and work on the background layer but I'm used to versions that didn't have adjustment layers and like to keep a virgin down there.
Select new layer, if not already selected or background layer if using it. Click on half-light half-dark circle at bottom of layer window to open Create fill/adjustment layer menu select Channel Mixer option, or select Layer-->New Adjustment Layer-->Channel mixer. Figure 3
The channel mixer window will normally come up with blue set at 100%. Check the monochrome button and also the preview button. Adjust values for individual red, green, & blue channels... good start is 45,60,15 respectively. Find a set of values that get the desired result and click ok to save the adjustment layer. The constant slider lightens and darkens. Figure 4
If desired, before closing channel mixer you can save the parameters for use next time, or save the generic start values and load them next time you open channel mixer.
You can also create another adjustment layer, a Hue/Saturation layer, and tint the b/w you just made. Be sure to click the colorize button in the Hue/Sat window. Set the saturation level to about 10-15 for starts and play to your hearts content. Figure 5
You may have already known this technique, if so, sorry to take up your time, if not, then you have another thing to play with in CS2.
