This looks like a great project. My only feedback is that in these types of situations, the tendency is for people to use the tools they already have. For the London riots that was BBM, for Tunisia and Egypt that was Facebook and Twitter.

This could be particularly problematic if you're targeting an internet blackout situation, because people will likely use the tools they have until they can't anymore, at which point it will be too late to download yours.

So you might think about positioning it differently, or coming up with an application for it that people will enjoy outside of a crisis situation, so that it will be one of those tools that people already have.