Place GameObject above screen

I was wondering what the formula would be to place an object perfectly off the screen rather then punching in a predefined value. Or if it can be done. I have a play with.

Screen.height Screen.currentResolution.height / 2;

The above 2 place the object way above the screen :0

I know I also need to probably add the GameObjects Scale/Height in some how.

To do something like that you can use ScreenToWorldPoint:

http://unity3d.com/support/documentation/ScriptReference/Camera.ScreenToWorldPoint.html