I've been a champion of the ideas behind "Web 2.0" for a long time, but I absolutely deplore the term - and probably as a result haven't talked about it as much here I would have. 

It's a general problem I have with most of these kinds of buzzwords used to decribed paradigm-shifting technologies: they're vague, overbroad, ill-defined, and most of all trivialize what is really going on in the first place.

Michael Swaine makes this point in the most recent edition of his always -excellent Swaine's Flames column.

Onions to "Web 2.0." Uhh, does Tim Berners-Lee get a say in when the Web gets revved? Or is it the rule that anybody named Tim gets to start his own Web? Internet2, IPv6, those terms actually refer to something. But Web 2.0: What's that exactly? Nobody seems to know. Last September Tim O'Reilly,
 who, along with his coconspirators at O'Reilly & Associates, coined the term, tried to explain what Web 2.0 was and/or wasn't. That essay convincingly demonstrated that Tim doesn't know either.

He did, however, attempt to define it himself.

If Tim (either of them) can't define it, I certainly shouldn't try, but I will anyway: Web 2.0 is a commemorative coin minted in celebration of the end of the dot-com crash. Like all commemorative coins, it has no actual value.

( Aside: it's rants like these that are probably the only reason I still read DDJ anymore )

As I've talked about in the past, we were doing the whole browser-as-rich-client thing back in 2000 (like many others). It was easier for us to innovate then because we were working in a closed environment. We had control over the browser and we knew we could rely on fat pipes between the server and client. That is now known, of course, as AJAX - a key element of most "Web 2.0" definitions and another just awful term that really missed the point. What is relevant about AJAX is not the Javascript and the XML, but the experience. Those specific technologies just happen to be a means to that end.

A little anecdote: I remember vividly a brainstorming session (for lack of a better word) I had with my father back in 1997 while visiting the college I eventually attended. We came up with some pretty cool ideas, and yet we summarily dismissed most of them as too unrealistic and "out there".  After all, could you imagine having to convince those offices to get a computer and - gasp - dial in for Internet access all day?

The reason I'm so excited now is because all the innovations in connectivity, hardware, and - perhaps most importantly - de-facto standards (like, say, RSS) have eliminated many of the constraints we once operated under.  It means we can move beyond the technical limitations that dictated how once did things and instead focus on the problem itself.  Where we were once concerned with whether a business would have a computer and an Internet connection, we now have always-on, high-speed connections in our pockets.

Of course, just because we can do something doesn't mean we should.  In my opinion, we went too far with a lot of the Javascript / Web stuff I mentioned previously. A lot of really was innovate, but some of it really didn't make sense either. After 4-5 years of doing everything in the browser, the pendulum finally started to swing back for us internally. That is, we finally realized that, hey, maybe data entry is better off in a desktop application than a web browser. We finally recognized that certain tasks are better suited in different contexts.

Paul Graham made this point nicely in his requisite "Web 2.0" article:

The fact that Google is a "Web 2.0" company shows that, while meaningful, the term is also rather bogus. It's like the word "allopathic." It just means doing things right, and it's a bad sign when you have a special word for that.

The revolutionary stuff does not happen when we do the same old thing in a new container. The revolutionary stuff is when we have ubiquitous access to our information and can interact with our world from any context we happen to be in - and with an experience scaled appropriately for that context. In other words, the experience should be different on a mobile phone than it should be on your beefy desktop with 3D graphics, 2GB of RAM and a speedy connection.

Don't worry, I'm not going to exercise my namesake privilege and invent a new Web. But if I were, I would define it as a world where the lines blur and boundaries are eliminated.