If you use Avangate as your payment processing partner you may need to download their current currency rates so that you can present the same rate conversion to your customers on your site. Avangate implement a simple XML based API where the following URL returns an XML Document containing the rates.
https://secure.avangate.com/content/exchange-xml.php?CURRENCY=USD
With Data Synchronsiation Studio you can implement a Synchronisation Import job to import this in about 2 minutes. Simply connect with the XML Provider and Specify the URL and Item XML XPath of //currency
Add 2 Columns csymbol and crate
And that is it preview the Data and setup the Synchronisation job to your Database.