In this tutorial, Mylenium will show you how to replicate that stylish MacOS X buttons look. At first sight it will look like an antiquated technique of a time when today's layer effects in Photoshop were also created that way, but after a while you will clearly see the advantages of it. Think of it more as a source of inspiration on how to overcome limitations of for instance the Alpha Bevel effect rather than a tutorial in its classical sense.
Adobe After Effects
Click on the link above to view this tutorial from Mylenium.