Grouping objects in level editor

Hi everybody!

I'm making a level editor game, and one of the features I want to implement is an object grouping system, so that users can select several objects at the same time, and edit their position as a group, a bit like object parenting...

Currently, I am using this code for object selection:

 var selectedObject : Transform;
 
 function Update () {
 if (Input.GetMouseButtonDown(0)) {
 var hit : RaycastHit;
 var ray : Ray = camera.main.ScreenPointToRay(Input.mousePosition);
 if (Physics.Raycast (ray, hit)) {
 selectedObject = hit.collider.gameObject.transform;
 }
 }
 }

Now I need to know, how could I implement this object grouping system? I assume I would have to use some sort of array, but I have no idea how to use arrays with Transforms, and what other complications that might lead to. :/

Thanks in advance!