In addition to running the very influential Web 2.0 site TechCrunch.com, and writing a blog called CrunchNotes.com, Mike Arrington has been working on a startup of his own called Edgeio (along with Keith Teare) – which Rob Hof of BusinessWeek got a demo of recently. Some might wonder why another kind of classified service is worth getting excited about, but the Edgeio model has an interesting and potentially disruptive twist. In a nutshell, listings of things for sale don’t have to be posted to a service such as eBay.com or Craigslist.com or BuyMyUselessCrap.com – they can live on your own blog or website, or anywhere. If they are tagged “listing,” Edgeio simply grabs them and indexes them.

This is the kind of extension of the “tagging” idea that really starts you thinking about what could be accomplished by simply tagging different items in a certain way and then indexing them. In a sense, it’s the ultimate expression of the “microchunking” idea, as venture capitalist Fred Wilson “edge” expert Umair Haque of Bubblegeneration calls it (thanks for the note, Umair). Let people find what they want wherever it happens to be. Tag a post on your blog “music review” and have it aggregrated; tag it with any number of other tags, and have them sorted and aggregated.

It’s a powerful idea, and in a way it accomplishes what the “structured blogging” crowd have been trying to get at, without all the coding and formatting. As Craig Donato of the classified search engine Oodle.com mentions in the comments below this post, there is also the “microformats” project, which is discussed here and an example of which can be seen here. A Swiss startup called Ichiba seems to be going for the same market, judging by the explanatory cartoon on their website.

On a somewhat related note, it will be interesting to see what kinds of conflicts of interest get declared when Mike launches Edgeio, given the recent story in the WSJ. Adam Green has more on that angle. Dave Winer, for one (who is an advisor to Edgeio), is already congratulating himself and wishing himself much success.”

Update:

As several people have pointed out to me, including one person whose comment appears below this post, what Edgeio has in mind isn’t exactly easy to do – the sheer brute strength required to somehow find and exclude all the inevitable spam listings would be similar to what Google and eBay.com have to do every day to prevent themselves from being deluged with fakery and phishing. So Mike and his company have set a pretty high bar to jump over, and it will be interesting to see if the product lives up to the promise.