From the Virgin Blue website (and I haven't tried it myself as I haven't booked a Vurgin Blue glight lately)
Virgin Blue has launched another initiative for travellers who book their flights online – Dynamic Currency Conversion. This service allows travellers with foreign credit cards to choose to pay for their flights in their local currency at the time of making their booking, rather than letting their bank convert the purchase into their local currency on their monthly credit card statement.
Launched this week on the Virgin Blue website, Dynamic Currency Conversion is a sophisticated IT innovation. It automatically recognises major foreign credit cards and displays the fare quote in the relevant foreign currency, converted in real time, to allow Guests the opportunity to purchase in their local currency.
The feature will be of particular benefit to international travelers, who can purchase Virgin Blue fares from anywhere in the world to travel on a network spanning 22 Australian and 8 International destinations