After much much contemplating and overlooking things, i have to say invisibilty suits/cloaks/whatever can not effectively hide something. Now this is because of the object. Unless it's a flat wall, no progress can b effectively made. Ill follow 2 theorys on how invisi suits would work.
1: Cameras film whats in front and displays image directly behind the camera on a screen. Now, this would be effective on a flat wall. If it was on a car or suit, it might look in invisible at one angle, but at all the rest, you would clearly be able see the shape of the disquised object in a distored mass of forget. Ill whip up some example pictures after school.
2: Bending light around the person. Now, if done somehow, youd be completely invisible to me. yet you'd see total darkness. Why? beause light is going around you, not into your eyes. Not very effective for hiding in the girls change room.
Ill whip up some example pix if you guys dont understand.