Perhaps someone more versed in film will be able to help me out: what is with the technique of starting a movie with a scene from later in the movie? What is this supposed to accomplish? Is it supposed to make the particular scene more meaningful? It gives away at least part of what will happen later in the movie. A couple of examples I can think of are from GoodFellas and Mission Impossible 3.
In GoodFellas where the movie starts with the guys driving in the car with Billy Batts still alive in the trunk. Then they stop and kill him. Of course this scene happens later in the movie when we see Tommy attack Billy Batts for the first time.
Or in Mission: Impossible when Tom Cruise is tied to his chair along with his girlfriend, and we are lead to believe he witnesses her death.
Is it just supposed to look cool? Or am I missing some important film technique and its meaning?
Other examples are welcome.