No True Barter?

I read recently that there has never been a true barter economy where money did not exist. The argument was put forward that there was always a medium of exchange used to measure value of the items being exchanged.
Currencies range from cigarettes, to yak dung, to carved sticks, to coins of precious metal, to paper money. Some currencies have inherent value- yak dung can be burned as fuel, cigarettes can smoked. Others do not, such as paper money, and their value is entirely symbolic and based only upon the survival of the system that uses that currency.

The dangers of currency are many.

If a currency does not decompose or otherwise expire in some way, then that currency will tend to accumulate into the hands of a few. Since money can be used to acquire more money, those with money will tend to use their money to get more money.

And thus an elite will form. An entirely symbolic or fiat currency is susceptible to shocks and panics since it exists only because the people believe that it does.

The primary danger of currency is that there is always a danger in a currency economy that people will transform from a citizen mindset to a consumer mindset.

I don't not know if I believe that there has never been a true barter economy, but whether or not this is the case a community planner looking to avoid the pitfalls of currency must assume that this assertion is so. A community planner who is designing an intentional community must do so assuming that currency will appear within the community, whether official or unofficial.

One method of controlling the form currency takes is the state sanctioned currency. Tally Sticks and Spartan coins are both excellent examples of this. By requiring that taxes be paid in the official currency, Lycurgus of Sparta and King Henry of England, forced the use of unpopular currencies.

Usury- that is the charging of interest on loans (or in modern terms, the charging of unfair interest) is something that civilizations throughout history have fought against. The Ancient Hebrews viewed any usury as criminal, since it allowed a man to profit without doing work himself. This allows for money to accumulate and for the rise of the banking and credit card systems. If a community planner wishes to curb these impulses, they must find a way to address the need that creates money-lending and loan sharking.

Loan sharking and money lending appear when people cannot get the basics that they need to make a living or improve their condition on their own and by their own labor. Mortgages are necessary in the first world, because almost nobody can afford to buy a home outright. Loan sharking in Bangladesh was noted to be a problem for the very poor, because they could not get raw materials for their craftwork without access to currency.

People without access to the tools they need, will turn to any other viable means of getting them. Therefore you need to be sure people have access to the proper tools needed. Members of your community must be able to craft a life from nothing, in the sense that they must step out into the world and be able to craft a life from the natural world around them, requiring nothing from your society if they choose.

Taxes as a weapon are another problem that must be addressed. The original South African diamond minds were reported worked by local African tribesmen, who worked just long enough to buy pots and rifles and the few modern conveniences they wanted before returning to the tribe. To secure a more reliable source of labour, the Diamond minds convinced the governments to institute taxes that must be paid in the official currency (a strategy that work for Lycurgus and Henry as mentioned above), therefore requiring the tribesman to seek employment to pay taxes created for the purpose of forcing them to work.

It is worth noting here that solving one problem may cause others, and one technique may work in one situation, but cause all manner of disruption in another. A planner must examine the situation carefully and likely also be willing to admit error and change when the situation isn't working.

Wealth and elitism are another notable problem that currency can create. The consequences of elitism is the marginalization and misuse of whole segments of the community.

Nations and communities throughout history have used different tools to combat this problem. 
Lycurgus of Rome cast heavy iron coins that he had quenched in vinegar to make them impossible to reforge. In doing so he made made money an arduous heavy burden, rather than something a person would wish to flaunt. The Haida prevented accumulation of wealth by having pot latches where people competed to prove their greater generosity, but still suffered from elitism based upon said generosity.

The important point here, is that currency is useful to facilitate trade and exchange between individuals. The danger here, is that currency can be used as a weapon by those who have it against those who do not. A smart community planner needs to craft a system of exchange (including either an planned "unofficial" currency, or an official currency) that allows for the exchange while protecting against the dangers.