Adding noise to a gradient image background is something I do often in photoshop. It helps avoid color banding when printing. It can also be a nice little effect when used correctly.
While I’ve used InDesign’s ability to add noise to my drop shadows and glows using the Effects panel, I never consider the ease with which I could avoid doing it all in Photoshop… that is, until I came across this Tip of the Week from Mike Rankin over at InDesignSecrets.
Add Grain Effects to Photos and Type shows you how easy it is. And for those that do use the Add Noise feature in Photoshop, you know how much storage space this is going to save you!