The makers of the iPhone have been expanding their retail presence in Australia, and in the past few years, have racked up over a dozen stores. Now, Apple is making it even easier for its customers to purchase accessories, provided they already have a recent iPhone.

Updated this week, Apple’s own “Apple Store” app allows you to now scan the barcodes of various products using the camera found on an iPhone 4 or iPhone 4S and pay for them with your iTunes account.

The service is called “EasyPay” and aims to let people walk in and purchase software and accessories easily, paying with the credit card or iTunes credit linked with their account.

Big ticket items like iPads, MacBook computers, and even Apple TV and Airport Express units can’t be purchased with the EasyPay system, however, so you’ll have to wait for one of the actual workers to grab those items.

Meanwhile, anyone itching to try the system can do so by grabbing the updated Apple Store app on their iPhone today and wandering into one of the giant’s retail shops.