Laser Cannons --> Military --> Spam

[deccan]

Here's an addition to Cyrien's list: international telecommunications (though not in the way that you hink. Also excerpted from The Economist:

IT ALL started with a ball hoisted up a flagpole. International telecommunications began in 1801, when the first link was established between the optical telegraph systems of Sweden and Denmark. Both networks consisted of lines of towers, each with a set of moveable panels on top. By replicating the configuration of panels at the next tower along the line, it was possible to transmit message over great distances with unprecedented speed. Such were the military benefits of this technology that a telecoms boom ensued.

Faced with the threat of an attack by the British fleet under Admiral Nelson, Sweden and Denmark had linked their telegraph networks to give them early warning. When Nelson attacked Copenhagen on April 2nd 1801, the news was transmitted to Sweden using the first ever network-to-network (or "internet") protocol. The panels on the Danish telegraph tower at Kronborg were configured to indicate that Copenhagen had been attacked. Across the Oresund strait, the Swedes hoisted a flag to show that they had received the message. The system worked flawlessly - except that the Swedes did nothing to aid Denmark, and the Danish fleet was defeated. Not for the Lasttime, the expectations raised by international telecommunications were disappointed.