Facebook, the social network that once upon a time required a school email address to join, is becoming the communications app of the moment. And not just for young folks, either.

A lot of businesspeople, big-time bloggers and others are headed to Facebook. Why? Its open API -- and the applications being developed for Facebook -- are transforming it into a truly useful social network. Blogger Jeff Pulver says he's migrating from LinkedIn to Facebook:

This morning I made the decision to focus all of my professional business social networking contacts to be on Facebook. That means that I am no longer going to accept new LinkedIn requests. After spending the past few months using Facebook, I no longer see the value of LinkedIn. Why use a static site where the fun stops at the profile when there is a wealth of opportunity for vibrant interaction between users and groups of users on Facebook? And since I come from the world where -- œan introduction is an endorsement -- I wasn't all that helpful most of the time when someone was trying to use me to connect to someone else on LinkedIn.

I have to agree with Jeff here. I've always thought LinkedIn was only part social network. You can create a large group of connections. But then what? There's no way to interact as a group. So it's really just a fancy address book, like Plaxo.

MySpace on the other hand seems to have had its 15 minutes. All I ever get there anymore are spam friend requests.

The point for communicators? Facebook is where everyone seems to be headed -- all the "eyeballs" -- so we'd better all be there. In fact, Robert Scoble, a key tech blogger, recently said that PR pitches are best sent to him via his Facebook wall:

And now we have a new way for PR people to let me know about their apps. Write it on the wall please. Facebook: the new press release.

Well, gotta run. Time to check my Facebook...

Technorati Tags: facebook, linkedin, myspace, jeff pulver, robert scoble, web 2.0