There are many ways to convert an image from color to black & white in Adobe Photoshop. I've posted tips before about this, but with Photoshop CS3, there's a dead-simple way to do it that produces great results, and offers you the ability to fine-tune your conversion.

Instead of simply selecting Image>Grayscale to convert your image to B&W, select Image>Adjustments>Black&White (Command + Option + Shift + B for you keyboard shortcut junkies).

In the resulting Black and White conversion dialog box, you'll be presented with the opportunity to adjust various colors in the conversion process. If you're familiar with how this works, you can adjust how each color in your image converts to gray. If that's a little more work than you wish to do, you can simply click on the image and move your cursor around to have Photoshop automatically adjust your image based on the sampled color.

As you can see in the image above, the normal Convert to Grayscale method produces a flat and quite dull image. Though this may work for some images, using the Black and White Adjustment allows you to to fine-tune your conversion to give you more contrast and retain more details in the image.