I have been reading Clay Shirky's new book,
Here Comes Everybody. The early chapters talk a lot about how new web tools are lowering the cost for self-organization. As a result, we are able to solve problems that a profit-driven market would not be incentivized to tackle. It also means that we can self-organize for other goals that would typically also not be supported by the market.
One of those unsuppoted goals is joy. I am a huge fan of using web tools to bring people together and to increase the joy per capita ratio in the world.
Improv Everywhere has been doing a great job of this since 2001. I wish them many more adventures and I hope that more people are out their scheming about how to put a smile on a stranger's face.