I love How Stuff Works (the show and the website) and I was curious for more information about the Advanced Research Project Agency (ARPA) and the interconnectedness of networks. I think it's interesting how many inventions or new ideas come about because of the government, and in this case, the government wanted to find a way to distribute information in the event of a catastrophe. The first model of ARPANET was only a network of 4 computers, linked together with phone lines and Interface Messaging Processors (IMPs). The computers' locations were chosen based on the location's relationship with the government: UCLA, Stanford Research Institute, UC Culler-Fried's Interactive Mathematics center, and the University of Utah.
For more info: ARPANET