Invoking an External WebService from Rails (WSDL...)

RoR nuby :

I'm trying to invoke an external WebService from Rails.

I've verified the Webservice works (see C# code).

URL : http://www.webservicex.net/WCF/ServiceDetails.aspx?SID=18
WSDL : http://www.webservicex.net/CurrencyConvertor.asmx?wsdl