"The Greek state is completely absent," says Katarina with a deep chuckle. We are standing across from each other inside a sweltering building on the outskirts of the Greek city of Volos, about 200 miles north of Athens on the Mediterranean. Both Katarina and her daughter, who stands beside her, have been unemployed for months. They are at this makeshift market to sell their array of homemade jams, pickled vegetables and liqueurs, which are spread out on the table between us.

But this isn't a typical market. In fact, there isn't a euro in sight. Katarina is part of a network of more than 500 people in Volos who are taking financial matters into their own hands as part of an alternative local currency, known here by its Greek acronym TEM. "In the network, people can trade their goods and services," says Christos Papaioannou, one of the network's founders. "If I do a service for you, then you owe me a favour. And I can use that favour to get some service from someone else. So, we don't have to exchange directly, I can get it from some third person."

To be clear, there is no actual currency or scrip exchanged. Credits are tracked via an open-source community banking software system called Cyclos. Katarina, for example, banks her credits from selling jam to buy staple foods such as eggs and fresh vegetables that are offered through the network.

The barter idea is catching on in a number of cities in Greece during these lean economic times, returning communities to a centuries old system but with a digital twist. And it's not just in Greece. The global economic downturn has created renewed interest worldwide in alternative economic models.

"I think that people are becoming increasingly aware, over the past few years, that financial systems aren't sustainable. And that boom and bust is always going to be with us, despite politicians continually telling us they are going to work to remove [them]," says Ken Banks, who recently launched a project called Means of Exchange. The idea behind the project, says Banks, is to create a "toolbox" of web-based and mobile apps that will make it easier for people to engage in things like bartering, swapping and alternative currencies.

“Cash-mob”

Banks certainly knows a thing or two about creating technology for development and social change. Back in 2005, he built FrontlineSMS, a mobile and web-based platform designed to allow communities to harness the power of text messaging to meet local needs. Today it is used for everything from election monitoring, dispensing legal advice to powering local radio talk shows.

While Banks has been thrilled with FrontlineSMS's success, the project completely consumed him. He says he kept a list of other ideas for potential projects but never had the time to follow them through. Then, earlier this year, Banks decided to step out of the day-to-day leadership role at FrontlineSMS. Spurred on by the very visible signs of the global economic crisis, the tackled the first item on his list: Means of Exchange.

“I was just seeing people having their lives trashed. I was reading about people lives being destroyed, people losing their homes, and really feeling it wasn't their fault in most cases," says Banks. "I started asking, 'how do you give people a little bit more control, buffer them slightly from the booms and busts of the system, and give people who care and want to do something a bit different the tools to enable them to do that?'"

Banks has already done his homework. For a couple of years, he has had two researchers looking into alternative currencies and barter systems around the world and feeding him ideas. Mostly, Banks says, he found that such projects failed to thrive because they could never reach a critical mass of users.

"A lot of the projects out there are not fun or engaging," says Banks. "People are missing a trick here. Where's the tech angle? Where's the social media angle? There needs to be rethink about how we build tools to help people succeed in these kinds of projects."

And so, in the interest of what Banks calls "fishing where the fish are," he says that Means of Exchange will focus heavily on mobile apps that harness the sharing power of Facebook and Twitter. He says one idea that has struck his fancy is something called "cash-mobbing," where people decide to descend en masse on, say, a candy store and each spend $5 or $10 each. It is very different from setting up a barter system, but still taps into the idea of communities helping each other out.

Imagine, Banks says, some kind of application that could allow individuals to easily set up a "cash-mob" like this with their friends. "People will do it because other people want to give it a go, feel like you're part of a community and people doing something cool and fun," says Banks. "And the fact that the shop keeper can stay in business for six more months is almost incidental to that. It’s a subliminal way of doing it."

Banks says he eventually would like to create a host of different applications that will allow individuals and communities to "pick and mix" depending on their specific needs. Not everyone will want to create an alternative currency, he notes, but maybe they would like some kind of credit system based on time or job-swapping. And some, he says, might one day want to expand the network farther afield.

"Maybe you could connect local communities up with each other, so that my village could then trade and barter and use whatever systems I've created with the next village, so I can actually use my units with the village down the road. You could make a virtual local trading area, by connecting up communities around each other."

But that's in the future. For now, Banks says, he's concentrating on making the Means of Exchange website a hub for anyone interested in these kinds of economic alternatives and developing the project’s first app, which will be available first on the site, but then also on mobile platforms such as iPhone and Android.

Banks says he is not in any rush. Like FrontlineSMS, he says, he believes that if he builds it “they will come." The trick, he says, is to have fun and engaging tools in place when people come looking for them.

"If I can get this right, I think it could be potentially much bigger than FrontlineSMS, because I just think the need is so great," says Banks.

"People are suffering through no fault of their own in many cases. They want more control over their lives, and we want to create self-help tools for those who want to rebuild something that was lost a long time ago in their communities."

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