Activating & Deactivating prefabs from a prefab pool VS simply moving them on and off-camera (iOS)

Thanks Jessy, but could you please be more specific? So moving the collectibles out of the viewable area when it has been collected, without deactivating it (using "gameObject.active = false;") is not using more resources (than if I had also deactivated it)? What component would it make sense deactivating (in order to spare resources I mean)? For example the collectible's "$$anonymous$$esh Renderer"?. I'll look into using event listeners as I don't yet know what they are.

Right, moving a game object is no big deal unless it has a static collider - use kinematic rigidbodies if you need to move things with colliders. Disabling renderers is the most obvious, but it depends on your game, what you need to do. Unfortunately, I don't know that there are any tutorials showing you how to integrates events into Unity; I never see anyone else using them, but of course most of the code on these community sites is just snippets, not reflecting an interwoven scripting system. Here is a small example, anyway: http://answers.unity3d.com/questions/34045

This was really helpful :)