Draw a cube. Pass this into handle functions.

Note: Use HandleUtility.GetHandleSize where you might want to have constant screen-sized handles.

Cube Cap on the Scene View.

	// Draw one cube on each axis of any GameObject that has 
	// the "DummyCubeCapScript.js" script attached.
	
	@CustomEditor (DummyCubeCapScript)
	class CubeCap extends Editor {
		
		var cubeSize : float = 1;
	
	    function OnSceneGUI () {
	    	Handles.color = Color.red;
	    	Handles.CubeCap(0,
				target.transform.position + Vector3(5,0,0),
				target.transform.rotation,
				cubeSize);
	    	Handles.color = Color.green;
	    	Handles.CubeCap(0,
				target.transform.position + Vector3(0,5,0),
				target.transform.rotation,
				cubeSize);    	
	    	Handles.color = Color.blue;
	    	Handles.CubeCap(0,
				target.transform.position + Vector3(0,0,5),
				target.transform.rotation,
				cubeSize);
	    }
	}

And the script attached to this Handle:

	//DummyCubeCapScript.js
	Debug.Log("I have CubeCap Handles attached to this transform!");