1928: Fifty percent of American households have radios. Television is still in developmental stages, but would eventually replace radio as a dominant means of entertainment and information.

Today: At least one television can be found in nearly every American household; many homes have multiple sets. Its primacy as an information and entertainment source is challenged by the Internet.

1928: The first talking film, Lights of New York, is released by Warner Bros. It uses the Vitaphone system. Some believe talking films are a fad that will go away. Separately, Kodak introduces color film stock.

Today: Movies feature increasingly better sound systems that use digital technology. There are also many ways of watching films outside of the theater, including DVD.

1928: Railroads are the primary means of crosscountry travel. Commercial aviation is in its infancy.

Today: Airplanes are the primary means of cross-country travel. Amtrak, the primary American...