Every so often, someone new will pop up to peddle the latest techno-aisling. These glorious visions of the future usually involve stereo sound and the Internet everywhere; video-phones in each room of your house; robots to make the toast; and of course fridges that re-stock themselves by sending SOS messages to the supermarket when the milk is running low. A central point in this is always digital television.

Seeing as there is still no sign of it, many people have by now become somewhat cynical about the digital future. But the first wave really is coming. Soon. Not by Christmas, perhaps, but certainly, for some, by the spring.

Digital service to the home has become shorthand for several things; more television channels, video on demand, fast Internet access, virtual shopping, voice telephony and more. Right now, there are three or four rival technologies that can deliver all or most of these within a year.

NTL, the company formerly known as Cablelink, and Irish Multichannel, owned by Princes' Holdings and the US cable giant TCI, will soon be wiring up their cable customers. By the middle of next year, most of these will have access to digital television. The companies are likely to give away the set-top boxes, needed to convert the signal for use by most televisions, for nothing.

RTE, a future shareholder in the Republic's as-yet-unformed digital television broadcasting company, is also working frantically on its future. By Christmas 2000, its set-top boxes should be atop Irish screens.

Meanwhile, Eircom is this month beginning trials of a new technology called ADSL, which transforms an ordinary phone line into an information pipe capable of sending video-quality signals to every subscriber.

The first thing people will notice will be the increase in channels available - the cable companies say they have the capacity to deliver up to 500 new stations. Even if they only visit an extra 200 channels upon the public, they will also have to supply some way of navigating through the dredge to the nuggets of good programming at the back.

This will be called the online programme guide, an interactive system that allows the viewer to select programmes first by category (news, sports, soaps, films, history, business etc), then choose what type of programme within each of these. The guide will also permit choice by time, or by name.

At first, viewers will also be able to access Near Video on Demand (NVOD), where they can choose from a dozen or so top films, starting every 15 minutes. As technology improves, they will get Video On Demand (VOD), and be able to choose from a large library of films, downloadable and watchable immediately.

Broadcast digital television will offer fewer stations, but instead of NVOD, viewers' set-top boxes will be able to rapid-store programmes they want to watch. Rather than have to programme this system like a video recorder, users will be able to simply point and click the remote control during a promo, or at a screen guide.

Eircom will not be providing normal television broadcasting with its ADSL technology, but will probably offer video on demand, from a large library of films.

Then there is the Internet, which will be built into the television system. This will allow browsing from the armchair, and online shopping. For example, a local pizza company might offer delivery within 10 minutes, "just click YES now!" Travel arrangements should also become easy to make online.

Customers will also be able to listen to music on demand. At one demonstration run by NTL, users could call up the lyrics of a pop song onscreen while listening to the song. They could also request the television to warn them five minutes before the song came on any channel, or record it.

Apart from Digico, all the companies will be providing telephone service too, probably bundled with the television service. No doubt this will make it very hard to compare prices.

But the interesting thing about technology is that those who invent it rarely predict, initially at least, how ordinary people will use it in their everyday lives. Which means the visionaries of the future will be in business for some time yet.