Years to reach a market audience of 50 million:

Radio: 38

TV: 13

Computer: 4

Number of Internet devices in ...

1984: 1,000

1992: 1 million

2006: 600 million

Travel from New York to California:

1848 wagon train: 5 to 6 months

1920 train: 3 days

2009 jet plane: about 5 hours

Humans have been evolving on Earth for around several million years, but it only took 66 years to go from the Wright brothers' flight (1903, above) to the Apollo 11 mission that put a man on the moon (1969, right).

Sources: "Shift Happens," by Karl Fisch; www.geocities.com; www.nasa.gov