NEWLYWEDS Austin Craig and Beccy Bingham-Craig are sitting in a Wendy's outlet on Lavender Street, a long way from home in Provo, Utah. In the last three months, the travelling American couple have not directly spent a single red, government-backed cent to get here: they have paid for everything in Bitcoin, the virtual currency used by a few and understood by even fewer.
Yesterday, in this corner of Singapore, the pair ended the final and 102nd day of their experiment called Life on Bitcoin, after having made pit stops in Berlin and Stockholm to meet fellow Bitcoiners.
In an interview on Thursday, Beccy told BT: "We've had people ask us, 'You've cheated, right?' But we haven't cheated at all."
The couple's experiment with Bitcoin - to be turned eventually into a documentary - started the day they returned to Utah from their honeymoon. To kick off the project, Beccy, who works with a data centre, converted her salary into Bitcoin. The couple paid their landlord in it. He took some persuading to accept this currency which is sent through the Internet - but not before taking a 10 per cent premium for his pains.
In their hometown, the couple persuaded a family-owned grocery store to take Bitcoin. To pay for petrol, they found a kindred Bitcoin spirit, an employee at a petrol station known to them only as Furb. They had to drive 80km from their home for the petrol though.
Then came the time to start their travel. In the last three weeks, the couple have driven cross-country to New York City, from where they visited Stockholm, Berlin and then Singapore.
Austin said: "I was curious about how to become involved in Bitcoin because neither of us is a cryptographer, programmer or an economist. As a concept, Bitcoin is really interesting."
Their trip has been equal parts madcap and careful planning. Their flights and hotel accommodation were arranged though Simply Travel, an online travel agency that accepts Bitcoin.
But getting a meal in Stockholm proved challenging. They wandered the streets ravenous late at night, in search of a restaurant that would accept Bitcoin. At a Burger King outlet, they found their US-issued gift card - paid for with Bitcoin - useless.
Beccy said of the Burger King staff: "They were like, 'We don't even have a way to accept this'. We looked crazy."
Since arriving in Singapore last Sunday, they have eaten at two cafes that accept Bitcoin. One of them, Artistry Cafe, has been doing so since July.
Where a direct Bitcoin transaction with a merchant is not possible, the couple rely on a fraternity of Bitcoin enthusiasts. In Singapore, a Bitcoiner helped them buy a local prepaid data plan for their cellphone in the conventional way, and accepted compensation in Bitcoin.
The couple's first Bitcoin transaction took place at a train station as they tried to get home from Salt Lake City's airport, post-honeymoon.
Austin said: "The first people we talked to had never heard of Bitcoin before, but we explained it to them.
"They said 'OK', and bought the train tickets, which we then bought from them with Bitcoin."
The experiment has been expensive: For the train tickets that cost US$18 in total, the couple parted with a physical Bitcoin - called a Casascius coin - worth US$45 then. Thanks to the rapid rise of Bitcoin's value, that coin is now worth about US$100.
The appreciation in Bitcoin's value that caused the couple to inadvertently enrich people in their wake made headlines in Norway recently. In 2009, engineer Kristoffer Koch bought US$24 in Bitcoin and promptly forgot about them. Four years later, that stash of Bitcoin rose to nearly US$886,000 in value, enabling him to buy an apartment in a swanky part of Oslo.
The cryptocurrency is approaching a full circle of sorts. It is now also available in physical coin and paper form, which contain "private keys" that give access to their digital value.
For all the pockets of euphoria about Bitcoin, the currency's value has a vexing tendency to plunge as suddenly as it spikes. In April, the price of a Bitcoin fell 70 per cent to US$70. Since then, the price has regained dizzying heights, trading at US$213 yesterday.
Compounding the volatility, Mt.Gox - the world's largest Bitcoin exchange - has earned the unwelcome attention of the authorities, becoming the subject of several raids. At last count, more than US$5 million has reportedly been seized from Mt.Gox accounts by the US government.
Little wonder then, that in the button-down world of bottom lines and shareholders, large corporations have backed away carefully from the Bitcoin concept.
Austin and Beccy found that for their project, buying a cellphone directly with Bitcoin was impossible. Austin said: "If a company is large . . . they say, 'We'll need to address that to corporate headquarters and that can take weeks or months or years if we can even get the conversation going'."
Even smaller businesses keep one wary eye on the vagaries of the Bitcoin world. Prashant Somosundram, owner of Artistry Cafe, puts a per-head cap on bills settled with Bitcoin. He told BT: "I'm quite conscious that this is still very nascent and any small technical issues could wipe out everything."
Even so, the going is good for now. In the last four months, 50 Bitcoin transactions have taken place at his cafe, which has seen the currency appreciate in value by 50 per cent.
Despite the uphill battle that Bitcoin faces, the converted have grown more fervent, drawn to its decentralised nature and the fact that it is impossible to counterfeit and is relatively free of transaction fees.
Austin said: "After all the difficulties we've been through, I'm still very much a believer."
Some time after the BT interview, a minor triumph was scored in Little India, where the couple convinced a henna tattoo artist to take Bitcoin as payment. "Beccy is the happy new owner of a henna-tattooed arm," Austin told BT in an email update.
Somewhere in Little India sits a mildly bemused owner of what might just be a piece of the future.