You can integrate your application directly with the Fedex web services and for example register packages for pick up with them.
So the good thing is that you can take their WSDL and send it through our SOAP Kit Utility. It generates the classes required and you can easily talk to their web service by calling some new methods generated by our utility app.
You can of course do the same with building the SOAP requests and parsing the replies yourself. For sending/receiving you can use our CURL plugin functions or simply a HTTPSocket.