Makes any Unity monobehaviour a singleton that inherits from it

Singleton.cs

//FROM http://www.glenstevens.ca/unity3d-best-practices/
public class Singleton<T> : MonoBehaviour where T : MonoBehaviour
{
   protected static T instance;

   /**
      Returns the instance of this singleton.
   */
   public static T Instance
   {
      get
      {
         if(instance == null)
         {
            instance = (T) FindObjectOfType(typeof(T));

            if (instance == null)
            {
               Debug.LogError("An instance of " + typeof(T) + 
                  " is needed in the scene, but there is none.");
            }
         }

         return instance;
      }
   }
}