The recent alliance between Nortel and Microsoft to push unified communications - collaborative working using email, VOIP, instant messaging and SMS to keep us in touch, any time, any place - got me thinking about an attempt not so long ago to arrange a get-together of some online acquaintances.

The reason was that as the date for the latter approached, more and more of those who'd said they would be there dropped out, citing various reasons why they had to be elsewhere, had overcommitted themselves, etc etc.

To anyone used to keeping their word whenever possible, the online world must be a strange one. People promise things without meaning it, or claim to be what they're not. Either they don't take what's said online as seriously as what's said offline or face-to-face - they're not "real friends" after all - or they say things they don't really mean.

And yet, one of my favourite bits of research, dating back three decades, is the "medical computer" story. I've never managed to find it since, perhaps because it took place way before the invention of the web.

As I recall it though, the gist was that researchers got in some volunteers who were told they'd be helping test a new medical program. Some were put in a room with a terminal - this was in the days before PCs, of course - which then asked all sorts of questions about their health, while others were interviewed by a doctor face-to-face.

There wasn't a computer program at all - the questions were coming from a researcher in another room with a second terminal. But the "computer users" were much more open about discussing their problems than the control group.

So the discovery was that people can be much more open and relaxed when there's no-one sitting opposite - presumably because there is no judgemental gaze to avoid, or disapproving looks.

What we're discovering now is that the same is true of online chat. People will tell complete strangers stuff they've not even told their spouses, and it's partly because of the layer of insulation provided by a screen and keyboard.

The problem is that there is a downside to that openness and relaxation too, in that people can also be more thoughtless and vile.

That means women getting abused and aggressively approached for sex, for example, because weirdos will say things to a disembodied name that they'd never dare say in person - not without both parties having half a bottle of vodka inside them, anyhow.

Virtual drunks, now there's a concept...

Whether it depends on the person - some will be more honest, others less - or on the topic and the circumstances, I don't know. But what I do know is that people act differently online.

That means some will may make promises they've no intention of keeping or haven't thought through. And as the comms and IT giants work to build instant messaging into almost everything, this is going to affect business decisions too, not just your arrangement to meet Jim82 or JennyJ under the clock at Waterloo next Friday .