A classic (it was published in 2005!) from Stowe Boyd on Social Software. Much of it has come to pass, but its nice to look back and see the connections. I particularly enjoyed his conclusion, the full effects of which are still a long way off...
Perhaps just as interesting as the way that social software is transforming group interaction, across different time zones or in the same room. Social software is destined to have a huge impact on how businesses get at their markets. So the essential elements of social software will be incorporated into more conventional software solutions, changing the way collaboration and communication is managed within and across businesses, and ultimately transforming how companies sell and interact with customers.