I finished my JSON-RPC and XML-RPC handlers for Tornado, and so I've thrown them up on Google Code. Now people can test my JSON-RPC v2.0 implementation on my jsonrpclib library. :) Which is just what everyone was dying to do, I'm sure. Usage is pretty simple, it's designed to be a.) pretty transparent and b.) easily ported between XML-RPC and JSON-RPC to compare speed, network transfer, etc. times. For example, here's the complete code for XML-RPC client (after installing Tornado and the TornadoRPC library):

To use JSON-RPC, you'd just change any instance of xml/XML to json/JSON. There are several benefits to using JSON, such as smaller transfer size, keyword arguments, notifications, etc., but to use it you are required to install my jsonrpclib implementation.