Having a computer in almost every American home (No. 5) has changed the way the world conducts business and how people communicate. Computers have gone from whirring behemoths to devices that fit in every room -- or every pocket.
"We see them in our cell phones, our PDAs," said Suzanne Kantra of Popular Science magazine. "Kids' toys in particular have taken off in the ability to be smart."
And just as computer use worldwide is exploding, the brains behind them -- the processors -- are getting smaller. Computer chips made the list at No. 9, and today a chip that you can balance on your fingertip can hold massive amounts of data.