Soon we'll be able to buy holidays as well as household goods at the supermarket, says Andrew Orlowski
What shall we have with the aubergines, the mineral water and the nappies? How about two weeks in Barbados?

Supermarkets are an obvious place to sell travel and holidays, not so much because they are convenient, but because they have the computer systems needed to handle these most complex of products.

"No one could have predicted five years ago that Tesco would be one of the biggest retailers of petrol," says Ray Vaughan of the software house Chauntry Corporation. "Waitrose and Sainsbury have massive technology infrastructures. With their experience of communications systems like electronic point of sales, they will be able to sell holidays much more efficiently than travel agents."

Not to be outmanoeuvred, the more techno-savvy agents are expanding into new markets, assailing couch potatoes with home-shopping holiday services and interactive kiosks. "These are complementary services to our branches," says Tony Anderson, European product development manager at Thomas Cook, whose multimedia travel kiosks are spreading into banks.

Travel agents were among the first people to become comfortable with on-line information. They have long had viewdata terminals connected to the computer reservation systems (CRSs), the vast databases ultimately owned by the airlines.

These CRSs are the technical keystone of the travel business. When you want to book a flight, the travel agent will log on to a CRS and make the booking down the line. Each system handles a mind-boggling quantity of information: with 330,000 bookings per day at peak season, the operators expect to process up to 2,000 transactions per second. They have to cope with hotels and car rental, as well as the complications of "wait-listing" a passenger against several different flights.

Because CRSs are a source of great power, they also generate friction. Airlines are suspicious that some travel agents favour one CRS over another. American Airlines has complained that French travel agents are biased towards the Amadeus system, for example, at the expense of the AA-owned Sabre CRS. The European Commission will shortly decide on a petition made by a number of small UK airlines, including British Midland and Jersey International. Their concern is the increasing cost of using the systems, specifically the Galileo CRS, in which British Airways has a 23 per cent stake. Although every airline pays the same fee, the owners in effect receive a refund through their share of the profits.

Once the agent is logged on, there is further potential for bias. The European Civil Aviation Conference code insists that airlines cannot put any pressure on agents to book with them, and even specifies how information is presented. Because larger airlines - especially those with an alphabetical advantage - can crowd the screens, the details must be presented in flight order.

All these problems could be avoided if it were the traveller, not the travel agent, who plugged into the CRS. "The technology is there for the airlines to go round travel agents," says Tim Stevens of the auditing bureau Aviation Solutions. "It can be turned on at any time."

CompuServe, the biggest commercial on-line service, is already linked to Eaasy Sabre, a version of American Airlines's CRS. This claims to provide flight schedules for almost all commercial airlines, and has access to 27,000 hotels and 52 car rental agencies. You can make reservations on line, and arrange for tickets to be delivered through travel agents or by post. The system has a number of twiddles, including the bargain-finder feature, which directs you to the lower air fares.

Some agents are trying to pre-empt mass desertion by moving towards direct selling. Thomas Cook has developed interactive kiosks using off-the-shelf PC hardware in partnership with NatWest. But the kiosks, with their touch- sensitive screens, credit-card readers and gigabyte of local memory, still rely on a human presence: a live two-way video link to a travel clerk in Peterborough.

Observers believe it is only a matter of time before direct access to a CRS - on the CompuServe model - becomes available through kiosks, or even as part of a "home shopping" system. Two obstacles remain: security and ease of use. "With home shopping, the problem of abuse becomes even greater," observes Mr Stevens. Travel agents will book a customer on more than one flight, even though he will fly only once - but there is a limit to the number of bookings they will make. A home shopper might feel no such restraint, and could book dozens of seats.

Customers will not be keen to wade through screens of unfriendly information. Ray Vaughan says the software needs to become smarter. "Now, the problem is that without the operator's brochure, you can't book anything. With fuzzy logic and pattern recognition, these front-ends should be smart enough to offer clever alternatives."

The communications giant AT&T Istel, which provides the network backbone for the travel agents' viewdata terminals, has also been examining home shopping. "It's an emotive subject in the travel industry," says Istel's marketing manager, Julian Palmer, "but it doesn't have to be. The opportunities are there for travel agents as well as tour operators."

The agents' best hope may lie in the merciful self-interest of the airlines themselves, who do not want to see them die. Agents are useful for striking bargains over mass booking discounts, for example, and understanding specific companies' travel policies. "The chain will remain in place, whatever," says Graham Rose, business communications manager for Galileo International, "but they have to give added value."