Email accessibility seems to be the most effective method for communicating in a timely fashion between businesses and clients and students and teachers. The business world today is looking for a timely response in communications. We have all experienced how phone tag is not effective in the least.

Just a couple of weeks ago, I played phone tag with a salesman at a new vendor. I did not have his email address. Ultimately, we were never able to get in touch with each other. Every time he called me, I was inside a big steel and concrete building where you get no cell signal. Every time I called him, it was later in the day and he was not available. So it was a huge effort in futility and I never got my question answered.

I don't think that using social networking sites is effective for the majority of communications because privacy is necessary. While email is not a secure transmission method, it is not being publicly posted and available to to the world to index and search. There is no delete button for online content. Once something is posted to a website, it is available forever. That's not true with email. Email can have digital signatures and expiration dates. So email is inherently a better and more private communication method than communication on some website. 

I'll concede that if you are trying to collaborate with several people on a project, then a collaboration website like Sharepoint is better than emailing documents around. Some people are using wikispaces and Google documents for this. I caution you about using these free resources that you do not control. When you use wikispaces and Google documents, or Facebook, Twitter, etc., the content you post is not private. I don't care what security settings you think you are using. Ultimately, that data is on THEIR servers which means they have all that content. So if you were working on a confidential project, it would be stupid to use any of those services for collaboration. A viable alternative is to use a Sharepoint site that YOUR company owns and controls. Thus, only you or people that you have authorized can access the data posted there.

Email is still the most timely of communication methods. Even if you are posting items to a discussion board or a Sharepoint site or a wiki site, you either have to go check that website or wait till you get an email that tells you that something new has been posted there. Then you have to go out and get that information. It didn't come to you like it would have if it would have been sent via email to begin with. Also, how many places do you want to be monitoring?

Let's consider the fact that most people in business have smartphones and are using email on those phones. Most IT departments are not going to allow Twitter or Facebook text message notifications to come to the phones. And when you consider that Twitter and Facebook is just riddled with viruses and malware, why would the IT department allow people to access those websites from the phones? So if email is used as a communication method, then the recipient gets the message right away.

Email is even better and more timely than voicemail. I have may occasions when I'm onsite working with a client and have no time to pick up voicemails. If someone has emailed me, I have a dramatically higher probability of getting their message and being able to respond to it right away. If I'm in a big steel and concrete building, I may not even know that someone has left me a voicemail for hours. But I would have gotten that email right away (not on the smartphone, but on a laptop).

There's another issue here which has to do with reasonable access. I think it is unreasonable for students or clients to think that their teachers or business contacts should be available 24x7. Email ends up helping this issue significantly. If someone leaves me a voicemail on a Saturday, there's no way I'm calling them back until Monday unless they are on fire. But if they send me an email, I may respond to them if I'm working at my computer. So email actually contributes to the timeliness of responses.