Watching films is part of growing up in our western world. In the cinema, on TV, and now on computers, films are at the heart of youth culture. Half of all 15 years olds go to the cinema at least once a month. Meanwhile, on any one evening on TV, there are over 40 films screened on multiple channels. Cinema audiences are on the increase and the market for downloading films is just getting going. What's more, and to the alarm of advertisers, these days young people are more likely to be watching a film...