As the Internet hits 40 this week, it's not difficult to to look back and see the changes it's brought to the world.

E-mail. Instant messaging. Buying and selling stocks online. Watching surgeries performed in real-time. All are now widespread activities thanks to the Internet.

The changes have been nothing less than astounding.

Businesses stay in touch with customers using Twitter and Facebook. CEOs are blogging about their companies and their daily activities. And move over presidential candidates and sports stars, now astronauts are Twittering from outer space.

Internet pioneer Leonard Kleinrock, one of the computer scientists at UCLA who on Sept. 2, 1969, created a network connection between two computers for the first time, said that while the Internet is turning 40, it's definitely not hitting middle age. In fact, far from it.

"The Internet has just reached its teenage years," Kleinrock said in an interview with Computerworld this week. "It's just beginning to flex its muscles. The fact that it's just gotten into its dark side - with spam and viruses and fraud -- means that it's like an [unruly] teenager. That too will pass as it matures."

So if the Internet is just at the ground floor, what's next?

"We're clearly not through the evolutionary stage," said Rob Enderle, an analyst with the Enderle Group. "Clearly, it's going to be taking the world and the human race in a quite different direction. We just don't know what the direction is yet. It may save us. It may doom us. But it's certainly going to change us."

:stroy: Full story: Computerworld