The fourth screen! Now here's a term Alvin Toffler must love. I'm surprised he didn't think of it, himself.

We're talking about communication mediums. The first screen was and is the cinema screen, the second would be television. The third screen (which coincides neatly with Toffler's third wave) is your PC screen and now the fourth screen is the mobile device.

Heady stuff. Even headier, check out this viral video I recently watched on Youtube put out by Nokia (yes, self-serving. But, very worthwhile regardless.).

I wrote about the quickly emerging mobile web about a year ago for this site. For the most part, the article holds up.

I'm not sure the mobile web has yet "hit critical mass". But, I don't know anyone who is disputing that we're really, really close.

The question is how is your business leveraging the mobile channel to reach more customers, streamline work flow and change the way your employees do their work.

What's unique about the fourth screen that businesses need to think about?

- It's intensely personal. Communicating to someone through their handheld comes with a visceral understanding that it is personalized and intimate. You are not broadcasting on a small screen. You are nichecasting on an individual screen.

- Information is a moving target. It's dynamic and being created and modified by the user as much as the original source pushing the content. Bottomline: you do not have control of the message.

- This is not just the stuff of the young. Generation mobile is growing up fast and they have parents, by the way. iPhones and other 3G devices aren't just for Manhattan hipsters, Silicon Valley geeks and early adopters anymore.

- A few years ago, transparency was the buzzword du jour. It still is. But more than ever, people want it their way and now. Customers truly don't understand waiting for what they want and getting it exactly how they want.There's a growing expectation that you can get whatever you want at the touch of a few buttons in the palm of your hand. Are you mobile accessible?

- If your employees aren't able to work and connect on the fly, you are likely hobbling them from doing their job well. This is especially true if they are in sales or do any kind of field work or business travel. The cubicle is increasingly irrelevant.