Mary was in a hurry - as always. As she drove into the store car park, her personal digital assistant (PDA) came to life. "Aisle 7, number 120."

As a regular shopper she could always count on being directed to the nearest empty parking space. Once inside, her PDA was even busier: yes, her pre-ordered groceries were ready for collection; the fish counter had some fresh red snapper which was one of her favourites - should that be added, too? Maybe with some lemongrass and noodles for a Thai supper? And next door, in fashions, Jane, her personal shopper had selected some new styles - would she be there in 10 minutes or so?

Mary checked into the centre's touch screen kiosk and downloaded warranty details of her daughter's cellphone to her PDA. She had bought it only two weeks ago and already Millie had broken it.

In the fashion shop, Jane checked the body scanner - no change in Mary's measurements despite that business trip to Paris! The simulator modelled the selected clothes on the screen while she examined the fabrics over a cup of coffee.

Hmmm...the green and blue dress was lovely - and that trouser suit would be perfect for the conference next week. Thirty minutes later, Mary and her packages, plus the replacement cellphone, were back at the car where the store attendant was ready to load her groceries. "Have a nice evening," he said as she drove out..

When a company such as IBM, the world leader in supplying point-of-sale terminals, admits that this business is in transition and it can even foresee a world where such devices may largely have disappeared, then something rather significant is happening in the world of in-store technology.

"Electronic point of sale (EPoS) is still big business," says Mike Muldoon, IBM chief for retail in Europe, "but retail formats are changing and we need to focus on the sort of systems that will be needed."

IBM's extensive research and development (R&D) projects are concentrating on components for mobile systems, as well as equipment to be used by consumers rather than sales staff. "We're looking to create an 'IBM-inside' model for these new generation devices," says Mr Muldoon.

An IBM television commercial in the US says it all: a tramp-like figure tours the supermarket filling his pockets with goodies. As he walks out of the store there is no alarm or frenetic security activity, simply an assistant handing him the receipt: the goods have been automatically scanned by wireless sensors and payment deducted from the tramp's stored value card.

Such seemingly futuristic scenarios are already technically possible: a system using wireless electromagnetic tags instead of bar codes was developed in South Africa in the 1990s. All shoppers needed to do was push the trolley past a bank of sensors to have the entire load scanned and charged. At that time, the cost was prohibitive and while the technology has been used by baggage handlers at airports it has yet to appear in a supermarket near you.

But costs are coming down, consumers are becoming more technically aware, and staff are proving difficult to hire and keep. The cost equations are already starting to look a little different - especially since the sort of expensive wireless broadband networks needed are finally becoming resilient and viable.

Starbucks, the coffee-shop chain, is installing wireless broadband networks in its North American stores so that customers can log on to the internet to pick up e-mails over a cup of coffee. "Around 20 per cent of the US workforce is on the move at any time of the day," says Deborah Honig, director of strategic development and new ventures at Starbucks. "These people are our customers and our research showed that they were looking for somewhere to plug in their laptops."

Starbucks also launched a stored-value card late last year allowing consumers to pay for their coffee by simply swiping the card in-store, while a trial in Seattle puts the coffee money onto a mobile phone so that customers can place an order and pay by dialling the store and using a short messaging system (SMS).

"Initially, we had the idea that people might like to order their coffee on the way to work using a cellphone or PDA, pay for it using a card, and then all they had to do is walk into the store and collect the cup," says Ms Honig. "In-store wireless broadband and stored value cards developed from there."

Costs of the broadband project were initially estimated at $10m, but Starbucks has cleverly persuaded its IT partners, which include Microsoft and Cisco, to foot the bill on the grounds that the business users logging in will be prime targets for other value-added services.

Gill Hide, head of retail at service company Conchango, believes that within five years the use of integrated wireless kiosks, touch tablets and PDAs, along with consumer cellphones in store will be commonplace. "Mobile telephones are part of the youth culture," she says. "These customers will willingly use their hand-helds for other applications. We expect that retailers targeting the youth market will be among the first to adopt these new wireless and mobile shopping formats."

Instead of conventional checkouts, tomorrow's sales staff are likely to be equipped with touch tablets or "rugged" PDAs that can be used to interrogate central systems to check on product information or availability, accept card payments or place orders. Staff will be able to accompany shoppers as they wander the aisles and complete transactions there and then rather than needing to report to a central checkout point.

Already US companies, such as consumer electronics specialist Best Buy, are using PDAs in this way and interest is growing. "The logistics for some products are a deterrent when it comes to completing the sale," says Joanne Walter, vice-president for future retailing at NCR.

"Queue-busting, where staff can approach shoppers waiting in line and check them out with a mobile terminal, are actually very slow to take off in the US. Handing the goods from shopper to assistant - especially if the customer didn't bother to pick up a basket - is awkward. And then there's the problem of wrapping the items or finding a carrier bag."

Wireless terminals

NCR is finding more interest in its portable till points. These are wheeled carts complete with wireless EPoS terminals, battery-powered peripherals, cash drawer and carrier bags which can be pushed around the store as need be or even used outside for seasonal promotions, such as Christmas trees.

Companies such as Powercart in North America are using new battery technology to create portable kiosks and checkouts that can run for several days on a single charge. The technology is also increasingly in the hands of consumers rather than store staff: hand-held bar code scanning units for shoppers to check their own shopping are already commonplace in supermarkets such as Safeway, Waitrose, Sainsbury and Albert Heijn in the Netherlands.

Similar units are used in department stores for wedding gift registry with customers able to build up a wish-list which can then be accessed by wedding guests using in-store kiosks. As wireless technology spreads, these devices are already starting to enable real-time interaction with prompts and selling messages while common standards mean that the applications can just as easily be accessed by consumer's own devices rather than a store kit - although that is probably a little further into the future.

Taking the concept further is the Personal Shopping Assistant (PSA) from Unipower Solutions. This is a touch-tablet which can be clipped onto a shopping trolley; an infra-red beacon system then tracks the customer through the store - and the tablet displays promotional messages associated with goods in the vicinity.

The system has been tested by supermarket chain Stop and Shop in the US, while Proctor and Gamble has been researching the unit at its Cincinnati development centre and believes that it can be effectively combined with loyalty card data to personalise the shopping trip and only promote goods which the customer is likely to buy.

Shopping centres are also adopting these new techniques: at the Bluewater centre in the south of England, customers can arrange for promotional messages and offers to be sent to their mobile phones while they are in the centre.

In the US, the Simon Property Group is using tiny hand-held scanners from Symbol Technologies allowing customers to wander through the centre logging the goods they want to buy, which are then wrapped and assembled at a collection point, while the customer relaxes over a cup of coffee.

Consumer familiarity with online banking is encouraging the use of payment kiosks in stores for loading value onto mobile pay-as-you go telephones and for paying store account bills. Interactive kiosks are also being used as context-based information tools in supermarket aisles providing nutritional data in the health food section, for example, or wine ideas in the drinks area.

At Virgin Megastores in the US, an IBM kiosk system is used to offer 30-second information clips and sound bites on any of the 250,000 CDs held in store. Shoppers simply scan the CD bar codes and sales of more obscure titles have increased significantly as a result.

"With web-based systems we're seeing seamless integration between shoppers using the internet at home and then moving to store kiosks," says NCR's Mrs Walter. "It's like a mosaic coming together, making it easy for customers to move between the real and virtual worlds."

Seamless world

Digital receipts are one of the new concepts in this seamless world. These are standard XML records of purchases which can be sent to customers, accessed on in-store kiosks or stored by the retailer - forever ending the paper chase for the printed receipt when goods need to be returned.

Smart and Final, a US grocery warehouse chain, with 233 stores from California to Florida, is implementing the ReceiptPlus solution from AfterBot. Customers can log onto the Smart and Final website and view detailed receipts of goods they have bought in stores.

Customers' receipts can be easily accessed at in-store kiosks if there are products to return or warranties to check. Furthermore, the store has an accurate record to help with credit card charge-back problems and possible fraudulent returns.

Office Depot, a US office equipment chain, is one of the key players in the Digital Receipts Alliance which is looking for ways to exploit this emerging technology still further.

So, back to Mary, mentioned earlier: it might be a few years yet before she manages her shopping trip quite so efficiently - but the technology elements are fitting into place, the costs are coming down and, as Joanne Walter says, "the mosaic" is finally coming together.

Advanced devices and concept products featured in our page one illustration include systems from IBM, NCR, AfterBot and Unipower.