Forum Moderators: buckworks
Most customers from overseas are familiar with USD conversion rates. Show them that rate and then give them the choice of paying whatever currency your credit card processor supports.
If your card processor supports USD, then don't show them other rates.
In our case, we show them HKD and during checkout the processor gives them the option of paying in USD, GBP, EUR and a few other currencies. Saves me the hassle of keeping rates updated and dealing with currency related questions from not-so-savvy buyers.