Imagine your e-mail could only receive and not send. It would not be much fun.
But for the first decade of web browsing it's been just like that. You can read webpages but only if there are special add-ons can you interact with them.
Flock is designed to let you write to the web as easily as you read it
Now somebody has launched a web browser that is designed to let you write to the web just as easily as you read it.
It's called Flock and - while it's only available as a "pre-release" - it's already achieved the business equivalent of headlining at Glastonbury: namely, an article in Business Week.
I met up with the guys who invented Flock at something called a "barcamp" in Amsterdam: they had taken over one floor of an old office building in Amsterdam docks and equipped it with beer, sliced bread, Red Bull and whiteboards.
Attendance was by word of mouth - and within minutes of the first bottle of Amstel being cracked open the place was buzzing with about 50 members of that maligned urban tribe - technology geeks.
A lot of them work for big companies, including one who works for the Pentagon. But they are all dedicated to the idea of free software written through open collaboration, known as open source.
The explosion in blogging has been a major factor of internet change
Here is why Flock is interesting: over the past two years, the way we use the internet has started to change.
We've started to use it to share information instead of just consuming it: there are three big businesses based on collaborative models of web use - Google, Amazon and eBay. They don't just sell you information - they use information you provide, aggregated with that of others - as one of the central propositions of the business.
On my Amazon homepage, for example, it is constantly telling me what other people have read who bought books I have bought. Its star rating system for books and its league table of sales are enough to make people in book publishing tremble.
The other big thing that has happened is blogging. There are now 20 million blogs being tracked by the website Technorati - it is doubling about every five months: 70,000 a day are being set up, with the Chinese currently piling into this activity just as the US/Europe appetite for blogging plateaus.
Paul Mason tried his own blog for the G8 conference
Blogs are personal web logs hosted on special websites that make it incredibly easy to write your thoughts, link them to other people's, post your photos, etc. My blog, Newsnig8t.com, during the G8 conference is an example.
A third emerging example of web collaboration is the "Wiki" - a collaborative work space on the web whose best product is Wikipedia, the collective encyclopaedia.
Now the thing about blogs, and about business sites you can interact with, is that a lot of the "two-way" functionality has had to be bolted on to the main programme we use to look at the internet, Microsoft Internet Explorer.
So, what Flock represents is the first coherent attempt to write a web browsing programme where all the interactive elements are part of the programme, not bolt-ons.
If I had shown you a modem in 1990 and said 'it allows you to send letters to people all over the world,' you might have said 'why do I want to?'
The emergence of Flock is part of a wider movement known as Web 2.0 - when computer programmes are released they always have a version number so this means we are going into "version two" of the internet.
Web 2.0 is getting some of the people I knew during the dotcom boom very excited.
Some of the very same people who were trying to finance dotcom businesses with venture capital are now piling into Web 2.0 - and at a recent Web 2.0 conference in San Francisco, many of the internet's visionaries were to be found.
Does it matter?
Now, the problem with getting your head round Web 2.0, blogging and Flock is that, as Newsnight's deputy editor keeps saying to me as he paces back and forth next to my desk, "What if I don't want to interact?"
My answer is this: if I had shown you something called a modem in 1990 and said: "You will want one of these because it allows you to send letters to people all over the world and even read presentations they've written," you might have said "why do I want to?"
How we look at the internet could be about to change dramatically
The answer is you don't know until, firstly, you've got used to it, and secondly, there are a lot of like-minded people doing it. This is called the "network effect" - things become more useful the more people adopt them.
I am not predicting Flock will wipe Microsoft Internet Explorer off the world's desktops, but the browser it is built on, Firefox, already has a 10% market share.
I do think the way we look at the internet is about to change dramatically. And with the open source movement getting further into the mainstream of business, programmes like Flock have a better chance than ever of shaping the change.
Paul Mason's report can be seen on Newsnight on Thursday 27 October, 2005 at 10.30pm on BBC Two