Visualizing the Twitter Network

Twitter's popularity had prompted several groups to develop new applications to visualize the Twitterverse. Check it out here: http://flowingdata.com/2008/03/12/17-ways-to-visualize-the-twitter-universe/

Visualizing networks is important to detect network properties, such as triadic closure or random links. As Twitter grows, it will be interesting to see how its concept of microblogging influences graph theory.

Visualizing a network is difficult to comprehend. This commercial does a decent job in a comedic way of visualizing the verizon network:
https://www.youtube.com/watch?v=70UzgxL3XFo

Verizon is notorious for recently providing a face for their network, along with a large crowd of people to help represent the immense size of their network. The Verizon commercials are made to advertise products and spread the brand name, but it is truly a brand for the people. A company like Verizon has been able to develop software and products to enable the world to stay connected, and it's amazing when you think about all of components of a social network of this stature.

I don't really understand how the "Twitter Social Network Analysis" works. Since you can choose who you want to follow and control who follows you, Twitter is a directed Social Network. Therefore you aren't necessarily viewing tweets of your followers. Wouldn't the graph represent this? Also, this causes me to think; is the rate that news spread affected by a directed Social Network? We can argue that you are choosing to only receive information from those that you want to, but your network is relatively easy to expand because you can follow everyone from Ashton Kutcher to CNN. However, others that you have no relationship with can choose to follow you and thus be receiving your tweets. So does a directed network speed or slow down the spread of information?