To help prevent caching, it's common practice to add a random number parameter. The jquery library actually does this for me with a parameter named '_'. However, it causes an exception in your code. For example, when I add a paramater '_=51351551324', I get back:

Traceback (most recent call last):
File "/usr/lib/python2.5/site-packages/CherryPy-3.1.2-py2.5.egg/cherrypy/_cprequest.py", line 606, in respond
cherrypy.response.body = self.handler()
File "/usr/lib/python2.5/site-packages/CherryPy-3.1.2-py2.5.egg/cherrypy/_cpdispatch.py", line 27, in __call__
test_callable_spec(self.callable, self.args, self.kwargs)
File "/usr/lib/python2.5/site-packages/CherryPy-3.1.2-py2.5.egg/cherrypy/_cpdispatch.py", line 99, in test_callable_spec
message="Missing parameters: %s" % ",".join(missing_args))
HTTPError: (404, 'Missing parameters: _authorized')