Apparently Hans Zimmer is getting people to record themselves saying some chant and then they will include them in the movie, IGN posted the story here (http://au.movies.ign.com/articles/121/1211672p1.html) and the place to go to if you want to be part of it is here (http://www.ujam.com/campaigns/darkknightrises/introduction).
I'd do this but I'm afraid my mom will call the cops.