Gaah, here we go again. Google is attaching video conferencing to its Gmail service. Gmail users, if they have a webcam and microphone, can now download a little utility and IM and talk to people as well as mailing them. The IM facility has been around for a while.

And we needed yet another one of these why, exactly?

Let me put it this way. My computer is a Mac, so it comes preloaded with all the stuff you need to communicate through video to other Mac users. I grant you I have no idea which of my friends qualify so I haven't used it but it's there. I also use Skype. This has its own IM product and video conference. I use MSN's messenger service (indeed I talk to the owner of this site through it quite happily) and I have Google's IM for when I want it.

The thing is, these services don't talk to each other. Let's draw a parallel with another technology - the telephone. I have a phone here that works on the British Telecom network. The owner of this website will have something else - let's say it's AT&T, it doesn't matter. The important part is that if I needed to call her I wouldn't need to install anything special for the networks to talk to each other. 40 years ago I'd have called the operator and they'd have set it up, now I just dial. It's the same with mobile phones. I have something running on 02 in the UK. I can call a colleague who's on Orange or any of the other services - or anyone in the world with a phone, if I know the code. These mobiles are comparatively recent technologies.

Then we come to the instant messenger and video conference services mentioned above. If I wanted to talk by video to someone who used, say, Gizmo, then it's frankly tough. The Google service won't talk to Gizmo, which in turn won't talk to Skype, which in get the idea. As a user, though, I don't much care which network my colleagues use, I just want to talk to them, message them or whatever else I need to do.

I appreciate there would be billing implications and other complications to sort out before any of this stuff becomes at all straightforward. But that's where it's got to go. At the moment it's just looking like a load of empire-building for Google, the owners of Skype (that's eBay) and the rest.

As if they'd think of such a thing.