Site Configuration - Currency Conversion/Currency Codes tab

An IPINFODB key is required so that Jomres can detect the user's location, which allows the system to set their default currency and country automatically. This is a free key and can be obtained from here.

An Open Exchange Rates key is required to automatically download and apply change rates from the Open Exchange Rates service. This means you don't need to constantly update exchange rates, the magic is done behind the scenes for you. Get a key here.