They say that money makes the world go round, but is it possible to go around the world without money?
Irishman Colin Turner thinks so, and is attempting to do just that.
The 44-year-old Dubliner believes that a world without money is "not just possible, but preferable and urgently necessary for humanity to progress".
He set off on foot from his home on Sunday, travelling first to Northern Ireland and on then on to Scotland.
With no cash to pay for transport, food or board, Mr Turner will be relying on his wits and the generosity of other people to help him on his way.
He arrived in Glasgow on Monday.
"I want to do my part to show that life beyond money is not just possible, but better," he said.
"So I am going to begin travelling around the world without money, using only our amazing human network and the inherent goodwill of people that I know is everywhere."
Mr Turner describes himself both as a professional musician and the founder of a movement known as the Free World Charter.
His charter consists of 10 principles that he believes have the potential to eradicate poverty and greed and "optimise life on Earth for all species".
Through his cashless global odyssey, he is preparing to put no money where his mouth is to prove that is it possible to live by his principles.
"For the first time in history, we have the skills and resources to create abundance in the world, eradicate scarcity and all its associated suffering through the effective use of technology."
"For example, right now, we could build an entirely automated farm in a famine-stricken area, to feed thousands of people, if we didn't have to think about cost, but instead just decided to do it.
"We don't need money to create a futuristic and abundant society, we just need to have the vision and to start working together to make it happen," Mr Turner said.
He is leaving behind his career as a guitarist, singer and music producer in Dublin, but is prepared to sing for his supper on his round-the-world trip.
Mr Turner is offering to work, help out, or play guitar, in exchange for food or shelter, but is determined not to buy goods or pay for meals or accommodation in the usual way.
And it seems there are people out there who are prepared to pick up his tab.
He said: "I have already received hundreds of offers of support from complete strangers all over the world, offering me free accommodation, food and transport, which has been absolutely overwhelming and even humbling."
The Dubliner acknowledges the influence of Peter Joseph's Zeitgeist movement and Jacque Fresco's The Venus Project in the development of his own philosophy.
Mr Turner is not the first person, or even the first Irishman, to attempt to survive without cash.
In 2009, business graduate Mark Boyle began a two-and-a-half year challenge to live without using money.
Living in a caravan on a farm near Bath in England, Mr Boyle lived off the land, growing his own food and making use of waste products that other people threw away.
The self-styled freeconomist has now urged other people to support his fellow Irishman.
"If you meet Colin Turner on the road, whether as a volunteer on your project or as a travel companion, welcome him with open arms. The work he is doing with the Free World Charter is of great importance," Mr Boyle said.
Mr Turner, who intends to head north from Dublin, towards Scotland, down to England and then into mainland Europe, said people must learn to "trust each other and work together again".
"There's a lot of stuff we need to re-learn about being human, so we may as well get started," he said.