IMAGINE walking into a department store, trying on a pair of shoes or moisturiser then pointing your mobile phone at the barcode to get a list of real-time pricing information from competitors offering the same pair of shoes or facial cream a few dollars cheaper just a few doors away.

It is a phenomenon known as ''showrooming'' and it is causing headaches for traditional retailers in the United States who are already under siege from the online price discounting that has wreaked havoc with their business models. For customers, the mobile commerce apps give them even greater power to compare prices while shopping.

In Australia, a few retailers have started experimenting with mobile apps but they have a long way to go to catch up to US retailers, says telecom consultant Paul Budde at BuddeComm.

Mr Budde estimates that Australians own more than one mobile phone each (a penetration rate of more than 120 per cent) and smartphones have more than 50 per cent penetration, which means it is only a matter of time before the apps are offered in Australia.

Woolworths was the first major retailer to launch an app last August with limited offerings, which included the ability to scan a product's barcode with their smartphone, add it to their shopping list, and then order and pay for their groceries, which are home delivered.

Discount department store chain Big W went a step further and launched a mobile app in November, with a key feature to scan a product in any competitor's store and get the comparable price at Big W. In the next few weeks it plans to expand the price comparison to more than 60,000 products and offer detailed product information on more than 20,000 items. Its corporate affairs manager, Clare Buchanan, said the upgrades will connect to online shopping to enable customers to compare prices as well as buy instantly from Big W for home delivery or layby. ''Even when you're standing in Kmart,'' Ms Buchanan said. ''It will also give customers tracking information about the progress of their order and SMS them when it's about to be delivered - this feature alone is anticipated to reduce call centre volumes by about 25 per cent,'' she said.

Fashion chain Sportsgirl is another early adopter of mobile commerce. The group's strategic brand manager, Prue Thomas, said introducing a mobile app was a no-brainer and it is growing faster than website sales.

''Our girls are on the phones 24/7 and we should be, too. They can purchase as much as they want from the mobile.''