It was getting late — for me, anyway, having flown in from “back east” as they say here in Cal. But, before I faded, I managed to catch part the opening evening sessions of the Emerging Technology Conference on Monday evening. I joined it in progress, after a great dinner with fellow bloggers Steve Borsch and Marc Orchant at a place called Buster’s Longboard Bar, which was full of surfing decor and photos. I was lovin’ it. (And the shark fish tacos were excellent.) Timoreillyddavidson But I then managed to slip into Tim O’Reilly’s session called “O’Reilly Radar” and was glad I did, because he uncorked a great new definition of Web 2.0 … at least one I hadn’t heard yet.

“Web 2.0 is not over and out yet,” he said. And he went on to to describe what now distinguishes Web 2.0. This is O’Reilly’s definition:

“Systems that harness network effects to get better the more people use them.”

I think that’s a great way to freshen up what’s become a bit of a tired term for many. Thank you, Tim! He went on to touch on a few companies that ostensibly fit this definition … or are poised to, anyway: Freebase, an open/shared structured database of the world’s knowledge … personal financial management site Wesabe (O’Reilly mentioned his firm is an investor) … and a stealthy investor market intelligence company called Mint.

“Web 2.0 is moving from consumer to mainstream business,” O’Reilly said. He ended his talk with a request of the audience: “Let us know when you see people having a lot of fun with technology. We want to know.” That’s a key reason so many people turn out for this event, I’ve decided — to learn what’s new and what’s fun. I think that’s great.

Speaking of which, Tim’s talk was followed by an absolutely fabulous magician act — actually, a “mathamagician” — named Art Benjamin. To say he wowed this largely developer crowd was an understatement. The guy was amazing, had lots of willing audience participants get up on stage, and got applause like you couldn’t believe. But, he was so good, he was making my brain ache. I was fading fast. So, off to the room I went, figuring I’d naturally be up way early and could blog then without falling asleep at my Powerbook. The first day’s sessions start in an hour or so.

Update: Forgot the photo credit. It was shot by Duncan Davidson and is from his Flickr set tagged “ETech.”