Today, Facebook goes public, and begins trading on the New York Stock Exchange at 11:00am Eastern time (the truly addicted stockwatchers may want to bookmark this). Amidst all the noise about IPOs and investments and whatnot today, I think it’s important to celebrate facebook for the social innovation it represents, something that makes it truly unique from the usual technology success stories. Though FB is going to do quite well today (it starts at $38 per share), the measure of Facebook as a company isn’t it’s stock price at the end of the day, it’s the legacy of the technology itself, and there’s no better metric for that than the social change catalyzed by Facebook in the Arab Spring.

As Wael Ghonim, one of the central figures in the Egyptian revolution, said on CNN:

I’m talking on behalf of Egypt. This revolution started online. This revolution started on Facebook. This revolution started in June 2010 when hundreds of thousands of Egyptians started collaborating content. We would post a video on Facebook that would be shared by 60,000 people on their walls within a few hours. I always said that if you want to liberate a society just give them the Internet.

Facebook was and remains integral to how the young Arab activists coordinated and communicated with each other – protest pages proliferated on Facebook, for example this Bahraini one with almost 100,000 likes, and one EGyptian man named his daughter “Facebook”. 60 minutes did a fascinating segment on how integral Facebook was to their revolution, because “it was the only video sharing platform available to Tunisians”

For its part, Facebook corporate policy is to avoid claiming explicit credit or involving itself in the political debate. This does insulate them to some degree from the consequences of their users’ actions – and makes it harder for other regimes to justify banning facebook outright.

Today is certainly a major milestone in Facebook’s corporate history – but there’s more to it than just another IPO. It’s a coming of age. Mubarak to Mark Zuckerberg and the rest of his hackers in Menlo Park!