When I am trying to connect 2 systems I prefer to think about functions rather than resources , basically create "namespaces" and have something like: www.myapp.com/api/namespace/function then simply pass all data in using POST vars and serialize anything more complicated into JSON then just have to other end return JSON or XML.
Sometimes I will implement a simple header system with some metadata that should be sent and received with each request.
Getting too worried about POST/GET/PUT seems silly when you can just give your functions appropriate names.
I prefer to think of this as SOAP extra light.