A: The masses got a close-up at the first demonstration of the "electrical speech machine" in Philadelphia, at the 1876 expo.

Introducing the telephone to the world, the first public demonstration offered proof that the human voice could be transmitted through wires.

By 1878, the telephone's inventor Graham Bell set up the first telephone exchange station in New Haven, Connecticut. Six years later, long distance calls were made between Boston, Massachusetts and New York City.

In 1904, the first wireless phone was introduced at the St. Louis Expo, and this brought telecommunications into a new era. Sixty years later, the first picture-display telephone, which allowed people to see each other while talking to one another, was displayed at the New York Expo by Bell Telephone Laboratories.

As people across the globe remain highly interested in telecommunications technology, such products continue to be one of the main attention-grabbers for visitors at world expos.