Turn Photoshop Layers On/Off in InDesign.
InDesign lets you control the visibility of layers in your placed Photoshop graphics. That can be pretty handy when you find yourself designing a series of related ads that require minor changes to the same image.
In InDesign, select a placed Photoshop graphic and choose Object > Object Layer Options. This gives you a dialog box where you can toggle the eyeball next to any layer to turn it on or off.
In this example, a photograph of clam chowder was used for a variety of ads. Some layouts needed a yellow background at the top half of the page, while others needed the existing background. An extra spoon was added for some versions. Using this trick, a single layered Photoshop file was all that was needed.
Here is how those layers appeared in the original Photoshop file.
Source: This tip comes from Jason Hoppe's mini-workshop Mastering Layers: InDesign, Illustrator & Acrobat. This popular session covered the many surprising ways layers interact between different Adobe CS3 applications. If you missed it the first time around, we're planning to bring this workshop back in May.