Shopping - what's it for anyway? You crawl through a traffic jam, load up the trolley, crawl back through another traffic jam and get home hot and cranky because you find you've forgotten the mustard/shampoo/ barbecue sauce. And you've got to do the same thing again the next week.

But here's another scenario: you park your trolley at the till, pay up and walk out, leaving the shop to pack up and deliver your goods to your home while you continue about your business, empty-handed and fancy free. Not just the weekly groceries either but that bulky duvet, the lagging jacket, the 30-piece dinner service, a portable barbecue - all things you could, in theory, stagger home with but which you'd rather not.

As a cyclist with a limited number of panniers, shopping, for me, can be a headache unless it's done at a store which delivers. Some do deliver and some pay lip service.

Habitat, for instance, offers free delivery within the Dublin area or levy a charge of £25 to deliver outside it. Small, in-store items they will hold at the back of their store for a week, until you can arrange collection. Marks &Spencer will deliver your goods to a nearby car-park.

Roches Stores, on the other hand, makes deliveries twice a week, the ESB has a free countrywide delivery service and most grocery stores provide some form of home delivery. Spar's spokesperson, Des Palmer, explains that the company, whose 360 individual stores operate under franchise, has no general policy on home deliveries, while Samantha Fitzgerald, marketing manager for SuperValu is an enthusiastic supporter of the delivery service: "We started free home deliveries 10 years ago. And because we're community based, it's a big selling point. In one area of Dublin, 10 per cent of our customers have their shopping delivered."

On Achill Island, the SuperValu store operates a travelling shop which gets out on the road five days a week and even delivers on the mainland. For some people, this is their only means of shopping, but because of the distances, some SuperValu stores in rural areas now make a £5 delivery charge.

Londis also offers home deliveries and although it's up to individual shopkeepers, it actively encourages them to provide a service since it clearly helps business to do so.

Of course, the truly painless way to shop is by fax or on-line. Tesco has set up an e-shopping facility which, theoretically, could reach 685,000 homes in certain parts of Ireland - that's if each one had access to e-mail. The standard charge is £7 - £2 more than in the UK - and if time is more important to you than money, this may be a good bet, provided you have e-mail, of course.

But there's more to shopping than shopping. You only have to look at the teenagers crowding the local shopping centre on a Saturday to see that. Or take a walk on a Thursday night in any supermarket for a sight of singletons eyeing each other's lifestyle purchases with a view to engineering a trolley bump at an opportune moment.

No, shopping is when you run into people you haven't seen for ages which, given the times that are in it, could even be the next-door neighbour.

For anyone living on their own or for an elderly person, an outing to the shops may be their one chance of talking to someone that day. For the elderly, therefore, and the incapacitated - as well as the socially isolated - a home delivery service is an opportunity to shop and have a chat at the check-out without having to be dependent on a friend or a relative to cart the shopping home.

The problem for some shops is to decide whether or not they can afford such a service. One rural store that delivers free to an elderly man who rarely strays beyond the boundaries of his townland described the weekly run as a charity, a social service as much as anything else.

This is what it amounts to even in some city stores. Sales assistants have recounted how they've regularly borrowed the manager's car to run elderly people and their shopping home.

And there are other problems. One store which previously had a home delivery service had to discontinue it when it was discovered that the man with the van was moonlighting.

"People were charged £3 per delivery, but with maybe 60 deliveries a week, that wasn't enough for him even to cover his insurance," the manager told me, "let alone pay tax."

If the shopper lives locally, a taxi home won't cost much more than that, but how many taxi ranks are sited within easy reach of a shopping centre?

The home delivery system seems to work best when shops such as Roches Stores and Londis have their own fleet of vans. Those who can't run to a fleet often use a delivery company that has eight or 10 vans out on the road at any one time. Farming out the job to the man in the white van is the weak link in the system.

Trevor Sargent of the Green Party says that one way to ameliorate the problem of shoppers' cars clogging up the highways is to encourage neighbourhood shopping. Capping regulations could be enforced, whereby stores can no longer build the sort of aircraft hangars which, in some countries, pass as shopping centres.

"There is constant tension, between the traders' need to make a profit and the wider social applications but, at the end of the day, it's a political act for people to support shopping facilities close to where they live. Consumer power is the only one left to the person in the street."

The equation is simple: the bigger the store the bigger the traffic jam. "But the developers will come under further pressure in the end," says Sargent, "when the congestion gets worse."

There are 1.2 million registered cars in the Republic and it's a safe bet most of them will be on the road this coming weekend, heading for the shops and some drivers will be asking the $64 million question: "Is this journey really necessary?"