This afternoon (or morning, depending where you are), an ongoing, rolling decentralized experiment in journalism goes live once again, as the Apple mediasphere covers today’s iPhone announcements through a distributed network of unaffiliated blogs and Twitter feeds.

The ad hoc network which self-forms several times a year exists because of a key confluence of facts: Apple fans want news of new products as soon as possible and Apple stopped live-streaming their announcements years ago.

So within moments of whatever announcements there are from Cupertino today, they’ll be tweeted and posted from the seats in the auditorium, followed quickly by photos and, occasionally, the rare rogue livestream from the audience.

The coverage, born out of necessity, is almost perfect for web and wireless, especially for those sneaking a peek at work. The key facts — along with instant analysis — are posted within minutes, without the network overhead of a live video stream. Clear photos, showing product demos, pricing and details lag only slightly, as the blog authors scramble to shoot and post quickly. Many of the pages carrying the coverage auto-reload with the newest material at the top.

Want to see it in action? Among the sites with announced coverage today: Engadget, Ars Technica, Macworld and Gizmodo.

Or just set your Twitter Search to “iPhone” and wait for the news to Tweet at you.

How many newspapers can say they’ve live-blogged local events so intensely? Talk about it in the comments.