For most of us in the business world, e-mail is an integral part of our work lives. But for the millennials -- the generation between ages 13 and 24 -- e-mail is for old people. That's right, the first form of communication that brought many of us into the online world is now as outdated as a leisure suit.

For younger Webizens, e-mail today is like sending a letter -- something you do when you have to but not a primary means of communication. For these users text messaging, instant messaging, and social networking sites are the ways they communicate and stay in touch.

But, does this mean that e-mail is totally destined for the ash heap? Or has it evolved into something else?

Cabell Gathman, a doctoral student at the University of Wisconsin at Madison researching the ways people use the Internet to maintain relationships, said e-mail has not entirely disappeared from teens' social lives; it has simply taken a different form.

MySpace and Facebook may be known for the photographs and message boards that dominate users' personal profile pages. But the social networking sites also provide heavily used private messaging systems that are similar to e-mail.

Still, signs of a significant shift are emerging.

Signs of this shift were evident last week during the horrible shootings at Virginia Tech. Students relied on text messaging and Web 2.0 technologies like blogs and social networks for updates and for social support.

University officials faced criticism for e-mailing out alerts more than two hours after the first wave of shootings. In the wake of this tragedy, technologists have called for universities to adopt technologies like text messaging to build more immediate alert systems instead of relying on systems like e-mail.

And this weekend, I saw up close just how important text messaging is to the younger generation at the National Texting Championship in New York City.

So why is e-mail dying? I think there are a couple of reasons. First, younger users want more controlled systems of messaging. The advantage of text messaging, IM, and social network sites, compared with e-mail, is that these systems are controlled by users' buddy lists. While spamming inside these modes of communications does happen, it's still much harder and more expensive to spam people through IM, text, and social networks than it is through e-mail.

The second is immediacy. IM is instant and so, too, is SMS. Social networks are immediate, too. E-mail is slower. Users have to wait for a response and e-mail communication isn't, in most cases, a real-time dialogue.

And the third reason is personalization. E-mail is a cold medium. It's not as personal as social networking, where message updates and friend connections extend users' online personas through their communications. Cell phones are, almost by definition, highly personal devices and, likewise, younger users see text messages as more intimate.

So what do you think? Is e-mail doomed? Will the millennials usher in an age with no e-mail? Or will these users be forced to adopt e-mail once they get into the work world?