It's great that the Iranian people can self-organise despite all the attempted censorship of the government, and certainly the free flow of information is a powerful tool in the hands of the people... but guns are powerful tools too.
It's also curious why they did not clamp down on Twitter. After all, the Chinese government had no trouble shutting down Twitter along with all the other tools of communication.
Here's another thought: if things like Twitter are such a powerful agent of change, perhaps there should be a non-profit that exists for the sole purpose of providing rapidly changing and shifting anonymising proxies to people everywhere, to make it so that it is effectively impossible for any government in the world to block something like Twitter.
With all that said, I wish the best of luck to the Iranian people, and I hope they prevail. This is a historic moment, and I hope their victory without bloodshed.