Today Google announced that Multi-Currency support e-commerce support is coming to Google Analytics over the next few weeks.
This means that you can track transaction metrics (such as total revenue, tax, and shipping) in multiple local currencies without visiting multiple websites. Instead, Google Analytics will convert these figures into the currency you have set in your profile.
This is a major benefit for e-commerce companies with an international customer base. Right now a total of 31 currencies are supported, including US dollars, Australian dollars, Euros, British Pounds, and Hong Kong dollars. A full list of supported currencies can be found in the GA profile currency drop-down menu.
According to Google, the conversion rate is based on data pulled from currency server, which is serving Google Billing. The value will be the daily exchange rate of the day before hit date. You can learn more about Multi-Currency support as well as access currency codes on the Google Developers website.