With current events in Iran demonstrating the impact of social media, it is worthwhile taking a look at what Clay Shirky (wikipedia) has to say about the changes internet social media is bringing. Clay gave this speech in May 2009.
Clay discusses events in Iran in this Q & A
I previously discussed Clay Shirky's thinking in Now We Can Do Big Things For Love.
People wanting to better understand the social and economic impact of internet technology would do well to seek out Shirky's writing and presentations.
hat tip @GuyKawasaki