OPINION:I'M STARTING a blog. I know, ridiculous - what is this, 2004? Until now the word "blogger" has come with connotations of having too much time on your hands and is often interchangeable with the words "mature student" (surely the most dispiriting term in the English language).

That was until I interviewed Clay Shirky (author of Here Comes Everybody) for this magazine, who has put me right.

I've always found plenty of reasons not to have one. Most importantly, I won't be able to keep it up - I've started a diary hundreds of times, so do I really need something else in my life to feel guilty about not doing? I'm already not going to the gym and am halfway through not writing a book.

Into this stew of indolence and procrastination I'll throw in the concrete stuff, like how will it make money? If it doesn't, then what's the point? I write for a living. I know it's not much, but am I giving this stuff away now?

And isn't every other blog now just PR crap, written by people who couldn't get a job in television and found themselves in their late thirties "heading up" the marketing department of a company based on an industrial estate in God knows where.

Even Wiredmagazine, the bible of the digerati, has called time: "Thinking about launching your own blog? Here's some friendly advice: don't. And, if you've already got one, pull the plug."

It's all gone corporate, they say, and the chances of being found if you are just one "mature student" out there in your bedroom posting your thoughts is next to zero because you'll be drowned out by the big dogs like Huffington Post (huffingtonpost.com) or Engadget (engadget.com).

Then there's Twitter, which is like blogging, only shorter. This has its own challenges; to a freelance journalist, the basic Twitter question - "What are you doing?" - sounds like an accusation. I'm working - can't you tell? Reading the papers is research.

Sadly, the window of time which saw Twitter as a genuine, people-based method of communication is rapidly closing. Only a few weeks ago, you could follow a Mad Menfeed written by some nutcase fan who was tweeting stories about the show, each haiku-like entry pared down to the requisite 140 characters.

Then, in a witless attempt to grab some cool of their own, the makers of Californicationcopied him, but writing in the name of one of their characters - another great idea from the guys in the ball pool.

All of the above counts for nothing, however, when put against what I'm calling the Hudson River issue, which cemented the notion that I was, not for the first time, out of whack with the times.

Janis Krums was on a ferry chugging down the Hudson River in New York when the US Airways flight 1549 landed in front of him. In that moment, Krums made a decision to Twitter what he was seeing: "There's a plane in the Hudson. I'm on the ferry going to pick up the people. Crazy," posted Krums, moments after the plane hit the water. He then quickly uploaded an image of passengers standing on the wings of the plane, waiting to be rescued.

Think about that for a moment. The most extraordinary news event of the year happens in front of you and your first response is to Twitter about it. No ringing up the New York Timesto try to sell them the story - or, indeed, the photo, the value of which might have been considerable.

Krums (and by the way "crumbs, a plane has landed on the Hudson" is exactly what my mother would have said in his position) is the first Twitter celebrity, someone whose fame was created entirely by the short-form blog, a sort of tweeting Lily Allen.

Appropriately, the rush of followers to his Twitter feed fell away just as sharply when he went back to telling us what he was doing on the days when a near-calamitous accident of global interest wasn't taking place 20 yards away from him.

But Krums' story is a case study in social networking psychology; in short, sharing is the new black. This is really difficult for a youngest-of-four hack whose whole career is based on selfishness.

If I were pushed to offer a personal philosophy it would be: "If you know something useful, keep it a secret until you can sell it to someone" which, let's face it, goes against the zeitgeist.

So I'm starting a blog. Not for money, nor for ego, nor because I want to build a brand of one. I'm doing it because I want to see if it is possible for a 40-year-old man to change.

As my wife said, seeing me bring home a chicken pasanda and pilau rice for one: "Good luck with that."