In a new post to his blog Kevin Schroeder shows how to use the Zend_Server component of the Zend Framework to make a script that automatically makes the server you need based off of the request type.
I've been doing some work with Adobe on some articles and one of them was on working with mobile clients with Flash. Well, me being the masochist I did more. What I did was write an example that worked as a full website, an Ajax website, a Flash service and an XML-RPC service. [...] In a plugin, which I will show you in a bit, I attached an instance of Zend_Server_Interface. Then in the controller I simple told it to do its thing, with the exception of handing the Service Mapping Description for JSON-RPC ($smd). That's it.
Because of how the XML-RPC, JSON and AMF servers are handled, they extend the main Zend_Server_Interface, making it easy to create them on the fly. He includes the code for both the sample controller and the plugin mentioned above. It checks for Ajax, AMF, XML and JSON request types and sets the service handler correctly. If there's not one, it falls back on the mapping.