This Christmas, families will gather around the PC's warm glow

PRESENT TENSE:IF YOU'RE A bit iffy about Pat Shortt now, you could be positively queasy by the end of Christmas. In the way that the BBC has identified David Tennant as its face of Christmas television, Shortt has been pushed forward to do the job for RTÉ. He has, then, been handed that very important job: to keep everyone happy.

Christmas poses a particular challenge to those whose job it is to entertain you and your entire extended family as they slump on the couch, several stone heavier and all argued out.

Television offers few truly communal moments any more (although The X Factorand The Late Late Showremain stalwart exceptions), but Christmas forces everyone on to the couch together for that annual ritual of complaining about what's on the telly.

The Christmas night movie long ago lost its lustre, given that by the time it turns up there's been time to see it on Sky Movies, buy the box set and then sell it on eBay as an antique. There is usually one big-name, wide-appeal movie available – this year RTÉ has The Devil Wears Prada– but the choice is limited by what can'tbe shown. It is why, near the top of Things a Continuity Announcer Will Never Say, is: "And now, our Big Christmas Movie is the network television premiere of Lars von Trier's Antichrist."

Slowly, though, the primacy of Christmas television has been eroded by other boxes. It would be interesting to know just how many families will gather around the television set but won’t watch television.

This Christmas will not be the pinnacle of sales for games such as Rock Band– and there is talk of a slump in the sales of Wii and other consoles with so-called "special" controllers – but there are still enough units being shifted that the Christmas night movie will be ignored so that the family can go for it on Guitar Hero.

For all that television has to accommodate several generations at once, this generation of games controllers has also managed to break that particular barrier in recent years, so that it’s won’t be too rare to find Granny playing Wii Olympics after Christmas dinner, hammering away with the controller with giddy fury.

Still, the television set offers that communal experience that a computer cannot match. The computer works on another level, in which people gather around it on a global scale, yet as individuals. In the domestic context, it is something that fractures families, in which the glow of the screen usually shines only on one face at a time. There is, though, an exception: Skype.

A colleague this week mentioned that this would be a Skype Christmas due to more people being abroad this year than before. In actuality, we’ve had several Skype Christmases, because it has for several years been a useful tool for migrants in Ireland who want to see their families – or their children.

It is, suggested my colleague, the only bit of proper science fiction that he remembers coming into being. This is true. It is the videophone, even if it is imperfect in its technology – of inconsistent quality, often broken. A time lag means that conversations can be terribly awkward, people’s sentences constantly crashing into each other. But it is a fantastic, simple and relatively effective way to bring families together across thousands of miles. In this paper’s Health Plus supplement, one gentleman talked of this new ritual. “My mother retired this year and went off and did computer classes with this in mind,” he said. “My wife’s mother, who is in her 70s, did a similar thing in Cork. It is fascinating – the grannies looking through the webcam!” Elsewhere, a Donegal company has set up a service for people who want to use Skype this year.

This, then, is the one moment when the computer screen beckons families around it, although the ritual involves making pre-appointed arrangements, accounting for time zones and dinner plans and then squeezing everyone into the shot. It means sending the presents to each other well in advance so that people very far apart can open them together. And Skype also makes for a strange family portrait, of people squinting to see better, or hovering on shoulders so that they can be seen. Of people wandering in and out, of passing the baby forward to the webcam. And to those who are away, it offers a pixellated, limited but entirely welcome view into the place they call home. And of the family gathered around the box.