Wow, this sounds great:

…the six-minute-long interactive movie is in the „choose you own adventure“ style and generates 16 different endings depending on the choices of the audience. During the adverts the audience are given 4 different questions to answer and which they need to text to a given number. The final version of the movie is compiled from the clips that gather the most votes (which is all handled digitally). (via Adverblog)

Fiat Cinema

There also is a campaign site offering the same for the home viewer. First, you select which type of scenes you want (my portuguese is not so good, so I just chose randomly):

fiat

and then you can see your „selfmade“ movie:

Fiat 2

Even though the idea of the campaign site is nice, the WOW-effect of sitting in a movie theater and being able to influence what’s on the big screen is of course much more amazing.

However, I hope they let it run 2-3 times at least, because if they only do that once, you won’t be able to getting a feeling how the movie changes from time to time and might even assume that it’s the same movie every day…