unity_screensize.js

private var screenScale : float;
private var scaledMatrix : Matrix4x4;	// for scaling.

function Start () {
	// for scaling.
	screenScale = Screen.width / 320.0f;	// for portlait only.
	scaledMatrix	= Matrix4x4.identity.Scale(Vector3(screenScale,screenScale,screenScale));
}

function OnGUI () {
	// for scaling.
	GUI.matrix = scaledMatrix;
	
	var sw : int = Screen.width/screenScale;
	var sh : int = Screen.height/screenScale;
	
	// layout GUI parts as 320x480 screen.
}