I was just ripped off by Virgin Blue of Australia when purchasing a ticket online. At no point in the booking process did the website offer me the choice between paying in Australian Dollars or my own currency (US Dollars). Only when I looked at my receipt did I see the disclosure that I was charged in US Dollars, after a 3.75% markup.

What really steams me is that they have the gall to add "Cardholder choice is final" on the receipt.