Long before the introduction of the metal coins and paper notes, many objects were used as forms of currency. These tended to be natural items that often had some inherent value as jewellery and were in a suitably limited supply. The list of primitive currencies is long, but amongst other things included the teeth of elks, wild boars and shark, the feathers of large birds, arrowheads, blankets, beads, even human skulls.

Although you'd be forgiven for thinking that the era of being able to pay for your pint with an elephant tail or dog teeth is over, there is still one place where the use of traditional currency lives on. Vanuatu's remote Pentecost Island has little in the way of coins or credit cards; instead the main currency of the island is the pig tusk.

With that in mind, Pentecost is perhaps not the place you'd expect to find banks with wealthy reserves, , cheque books and tight security, but the island's Tari Bunia Bank, (which has several branches on the island) is just like a regular bank in any other part of the world. Customers can make deposits, take out loans and mortgages, and even enjoy a 15 per cent interest rate on their pig tusk savings. For hundreds of years, tusks, shells and rocks have been used for trading on these pacific islands, but the Tari Bunia Bank has taken these primitive systems to a new level of sophistication with its banking services.

In the bank's vault, thousands of pig tusks hang from the walls. The currency, which is called Livato, can be used to pay for everything from school fees to medical care. On a western scale, Vanuatu ranks as one of the poorest and least developed on the planet. But a survey last year found Vanuatu to be the world's happiest country - proving once and for all that money does not necessarily equate to happiness.

Pentecost's tribal leaders are hoping that their pig tusks could be one day be recognised as an official currency on the world market - but you've got to wonder - what would pigs would have to say about that?