That point is, as Adam Tinworth says is moving “from something that is used by the social media cognoscenti amongst journalists, to something that is rapidly spreading amongst the more web aware hack.”

Although Twitter’s use as a breaking news source isn’t exactly a new thing [1], with a growing number of users and an increasing number of both journalists and users all over the globe, it’s now reached the point where it’s the first place people are looking when something breaks.

And it’s also now become the norm that newspapers are reporting about the immediacy of breaking news on Twitter, as opposed to treating it as an interesting sideshow. Witness the Telegraph’s very good write up of yesterday’s New York plane crash.

That crash, along with the Mumbai attacks, seems to have convinced sceptical journalists to at least give the service a go. And once journalists try out something new, they’ll write about it, even if only a limited number of people are using it. That’ll then bump up the number of people who give it a go [2].

In the past few days, I’ve seen a serious rise in the number of people I personally know joining Twitter, while the number of people following me has also risen dramatically (I think they’ve nearly doubled already this month), as has our corporate accounts at work.

Having a slew of famous names join as well has also given it credibility. Never mind the sneering articles written about these (although, and I may be along in this, I thought Bryony Gordon’s piece was quite funny), the fact you have such a diverse range of celebs on there shows there’s an appeal across a range of personalities.

Stephen Fry, Robert Llewellyn, Will Carling, and Andy Murray have all helped. And then there’s Jonathan Ross, courting controversy with a few comments, but also quickly becoming the Twitterer’s favourite celebrity.

Ross, will his huge contacts book, has been verifying celebrities as they join Twitter (or don’t), and last night posted photos of him introducing the service to Danny Wallace and Eddie Izzard.

Phillip Schofield, who I think is the first ITV celeb to join, got Tweeting on Monday and has lept straight in, and is already being inundated with plenty of Twitter love. He’s already proving to be a great role model on how to use the service [3].

So, Twitter is finally moving into the mainstream now that it’s moved beyond a curiosity and into a genuinely useful communication tool (not that it wasn’t already). Quite where it goes from here, and how it goes, I have no idea. But it’s going to be fascinating to see how the site develops in the next few months.

And it also means I can probably stop banging on about how and why journalists should use it, because they’re now doing just that. Which will probably come as a relief to everybody.

[1] See the Exeter bomb blast last year.

[2] See also: The Wire. Until a few months ago, the only people I knew who’d actually watched this were Guardian journalists and people who knew Guardian journalists. That sentence hasn’t even been written for comic effect.

[3] And, about half an hour ago, gave me advice on the best organic veg box company to use in London.

Techcrunch notes that Twitter was talking about the terrorist attacks before the media cottoned on to the fact there was something major happening in the Indian City, and says that there’s no doubt that Twitter should now be considered a proper news source.

“You can jump up and down and shout all you want that Twitter isn’t a real news source. But all you are doing is viewing the world through a reality lens that’s way outdated. People want information fast and raw from people who are on the scene. If it gets a little messy along the way, that’s ok. We’ll soon see tools that help us distill the really good stuff out of the stream anyway.”

Global Voices back this up and goes as far to say that Twitter gives a better sense of what’s happening on the ground than traditional media could do.

“While the TV and media reports have been accused of using sensationalism and inflicting more terror from rumors, the twitter feeds portray the real sense of what is happening and how people are coping with it”

Twitter’s accuracy as a news source is picked up on in both posts, but it’s worth noting that with any breaking news, the exact story can often be unclear. I’ve worked on or followed numerous breaking stories where the information is contradictory, and what is taken as fact one hour can be shown up as utter garbage the next.

That isn’t necessarily the fault of the media or journalists – it just reflects the chaotic nature of breaking news, as do Twitter updates. But one of the most valuable aspects of using Twitter as a news source is the immediacy of the Tweets, and the swiftness with which incorrect information is corrected.

How accurate is Twitter? Well, look at the relevant  # channel for any given story and with a small amount of cross referencing, it’s easier to built up a picture of which tweets are giving the most accurate picture.

It’s not just the 140 character Tweets that make Twitter so useful for breaking stories. As Duffman notes, video-streaming applications like 12 Seconds, Seesmic, Phreadz, and Qik all post to Twitter feeds direct from a mobile.

“It’s this element of citizen journalism that some professional hacks may not like because they’ve become so used to using news wires to break stories that all they have to give them an edge over the rest of us is the quality of the coverage. Others recognise its potential and get involved.

Twitter empowers citizen journalists and allows them to not only report on on the spot but more importantly, enables them to reach a huge audience. Its not a complete solution as it lacks the objectivity in the same way embedded journalism does. However, it doesn’t go through the usual news media prism and is received without being framed to suit anyone else’s agenda. That, for me is its true value.”

It’s not just Twitter that was a useful news source for the Mumbai attacks. Charles Arthur reports that Flickr – the photo sharing site – quickly got a stream of pictures up direct from the scene (and it’s pretty hard to question their authenticity).

There’s also been Google maps mashups, along with the more traditional source of blogging and an ever-changing Wikipedia page. Journalism.co.uk and The Guardian have good roundups.

It doesn’t take a genius to work out that anybody who tracks the right topics across these platforms will be able to pull together a pretty accurate picture of how the story’s unfolding – a picture that may well be more accurate than news being reported through more traditional outlets.

This is something that became readily apparent during my tracking of the Exeter bomb blast in Giraffe earlier this year and has already grown beyond my findings back then.

Tracking the story via social media is, of course, no substitute for being on the ground. But if you’ve got a reporter liaising frequently with a colleague who’s pulling in as much information as possible from social media (and other sources), that can produce some impressive journalism.

What’s also fascinating is that for the Mumbai terror attacks, most major news websites were liveblogging. It shows how online reporting has moved on in just a few years. When Nosemonkey liveblogged the 7/7 bombings, much of the mainstream media treated it as an interesting curiosity. Now, a liveblog for a major news event – complete with links to other blogs, Twitter feeds, maps mashups, and the like – is pretty much industry standard.

With each major news event, it becomes clear that social media often has the most immediate coverage – and it’s a foolhardy journalist who chooses to ignore this.

That said, while social media may be the place to start looking for news during the event and in the immediate aftermath, once it comes to taking the story on and providing richer background analysis, traditional media comes back into its own. It has the time and the resources to devote to journalism.

What events like the Mumbai terror attacks show is that we all have the potential to be online citizen journalists. It’s never been easier to get breaking news out on the web – all you need is a half-decent mobile phone.