Alpha on a GameObject?

Is it possible to define the master visibility of a GameObject/mesh renderer? I am vaguely aware that fading a mesh out can be done by getting its material and changing the alpha value of it. However, perhaps my Blitz Basic 3D legacy has spoilt me with this feature, but I like the idea of an object opacity variable. Is there anything like this in Unity? For example, if I have a hypothetic complex object with dozens of materials it seems clumsy getting them all and fiddling with the alpha.

Is there a much better way to fade out a mesh that I am overlooking?

You could write a script with a single opacity variable and code that iterates through the materials of the game object it's attached to (e.g. via renderer.materials) and adjusts the alpha of each one.

technicat is right, this is the way to go.

When you're there, you might also consider using the two pass transparency shader to get rid of the overlapping polygons artifacts.