Over the weekend, Aussies took to one of Sydney's oldest pubs, the Old Fitzroy, but with new technology. It was the first time in Australia that the crypto-currency Bitcoin has been used commercially to purchase a beer.

Pictured are Marketcoin founder Max Kaye and BitPOS founder Jason Williams, who help run and organise BitcoinSyd, and Old Fitzroy proprietor Garry Pasfield.

Here's something that is rarely ever seen on a receipt: $0 in cash or credit. The register ties in with Williams' BitPOS system to allow payments to be accepted electronically, but of course, older systems need a bit of a tweak to get things working.

Williams gives a couple of mates a call to come down to the pub (at least, we think that's what's happening).

And sure enough, it wasn't long before he managed to build up a crowd for the Sunday afternoon.

Members from BitcoinSyd are on hand to help out with making transactions, and, if need be, provide a means for newcomers to the currency to purchase some.

On the merchant side of the transaction, a QR code is created that specifies which Bitcoin wallet the funds are meant to be paid into, and how much it costs.

This in turn is presented to the customer, who scans the code from their Bitcoin wallet app to make a payment.

Although chargebacks aren't possible under the crypto-currency, if the Old Fitzroy somehow runs out of beer and needs to make a refund, a transaction in the opposite direction is made, much like how cash is handed over.

Even the band is in on the act, displaying a QR code that will allow it to accept tips via Bitcoin.

The crowd gathers to hear from the author of The Idiot's Guide to Bitcoin, Gustaf Van Wyk. The guide aims to help educate on how Bitcoin works, from its decentralisation to why mining exists.

Van Wyk is currently in the process of raising funds on Pozible to publish a physical copy of the guide. Unfortunately, Pozible doesn't accept funding in Bitcoin at the moment, so he is accepting contributions in fiat currency.

Perhaps one day, banners won't be necessary, but until then, the Old Fitzroy advertises the fact that it accepts Bitcoin.