Just trying to clarify some confusion. From my understanding, we can use Salesforce to make Web Service Callouts in an Asynchronous manner in 3 different ways; using @Future, Outbound Messages and Batch Apex. Can these methods be used to call Synchronous Web Services? What I mean is, what if the Web Service is of a Request and Reply nature where the control is hung until the reply is received from the Web Service. Can the asynchronous methods handle the reply?
I know it works the other way around. So, if we call a Web Service Synchronously without using @Future, we can still call an asynchronous Web Service, which is of type Fire and Forget.
I hope I explained this well.