Culture Hacker features a great article on new ways to raise money to produce a movie. It is worth reading.
The old movie business model is simple: Get an Investor, produce a movie and use advertising to get people watching.
The Transmedia Model is slighly different: A filmmaker starts by promoting the fictional world,he wants to make a movie about,with low cost media (trailer, comic, literature....). He tells stories around the movie, shares and discuss it with the online community, without spoiling his core ideas. The goal is to raise awareness and to build an audience that convinces investors to finance the movie.
I think both models will work out in the future. But the Transmedia Molde might be more interesting for independent filmmakers, who have difficulties raising money.
The simple truth behind the concept is: Go public with your ideas from the very beginning. Find people that believe in you and want to see the movie. Engage with them to make the movie come true.