The Kaching! product means that customers, via the app, can pay each other via email, Facebook and mobile, and via an iCarte case for iPhone, or pay via MasterCard's contactless PayPass terminals. Users don't have to be Commonwealth Bank customers to receive payments, either, with non-bank customers directed to an external collection site.

The app will be compatible with iOS 4.3 and above, according to the bank, with cases designed for the iPhone 4 and 4S.

When paying, users can choose to pay via an address book, a Facebook friends list or a phone number. CommBank's sample image shows that if you really want to, you can pay Summer Glau of Firefly fame. Nice.

You can choose from a list of your Facebook friends to pay and even post on their wall once your payment is processed. A little creepy, but we guess that's the modus operandi of the social network.

Lark said that Facebook has been an incredible partner to work with throughout the entire process, and saw the relationship progressing into virtual currency territory via the Kaching! app.

"We're working hard with Facebook on [integrating Facebook Credits], and we hope to do interesting things there. I think there are hundreds of applications that get spawned when you start doing that. There are merchants who can offer coupons and deals inside Facebook, [as well as] Living Social, Twitter.

"We have this long list of people we want to go and enable next. We're really excited about the opportunity, but we had to start somewhere and we couldn't bite everything off at once," Lark said.

Users can also pay bills via BPAY on the new Kaching! app.

Lark said that while the Kaching! app is also being developed from the ground up for Android (rather than an iOS app ported across), the bank has no plans to develop an NFC-capable case for the Android contingent.

He did say, however, that the Commonwealth Bank had met with Google, who indicated a native NFC chip to be used by the bank would be ready within 12 months, at which time Lark hopes to have a partnership on the way for Google's Wallet product.

"We hope [to partner with Google Wallet]. We were up in Silicon Valley last week talking to Google," Lark said, adding that "there's a lot of hype around Google Wallet, but it really does depend heavily on the NFC element in the device. The reality is that they're testing that in the US now in a limited way, and testing in one or two European markets in a very limited way. Where Australia will sit on their test list, who knows?"

"The critical mythology in the market today is that all these Android phones in the market today have NFC chips in them. They actually have 'dumb' chips in them, and Google, based on what we've seen so far, doesn't look like they'll be in the market for at least 12 months with an NFC-enabled phone.

"It's not enough to have the chip in it; you have to have it enabled, and the 'secure element' has to be available to us as an institution so we can turn it on for you," he said.

The app also uses the iPhone's GPS facilities to locate branches and ATMs close by if you need to get your hands on some good, old-fashioned cash money.

The app is also secured by either a four-digit PIN number or an alphanumeric password. In this screenshot, you can also see that the NFC is on by default for quick payments from the password lock screen. It has a security timeout of 60 seconds, but settings allow you to disable this activated NFC on launch business.

The myriad of features available on the payments screen, including transfer between your own accounts, pay others via BPAY, email or Facebook and mobile payments.