Sharpening with Alt/Option key
Camera Raw 4.1 introduced some killer new sharpening sliders that let you get a lot more sharpening work done before you ever even get into Photoshop. One cool trick when using the sliders is to press-and-hold the Alt (PC: Option) key when you drag them. This lets you see a grayscale image preview of that specific sharpening setting.
Word of caution, I think I’m right in saying that you don’t see the result of your sharpening unless you are at 100% view level.