Something like asynchronous XML-RPC possible?

[Skip Montanaro]

    Will> As Stuart guessed, the application is indeed sort of realtime,
    Will> they want the caller to continue processing *immediately* after
    Will> sending the event to the server....

How "realtime" is "sort of realtime"?  Are you on a fast enough, lightly
loaded enough network?  You may still be able to get away with a system
which queues the event on the server side and just returns "okay".  On my
XML-RPC server, I can call its echo method with very short turnaround times:

    >>> for i in range(10):
    ...   t = time.time()
    ...   x = manatee.echo("hi")
    ...   print "%.2f" % (time.time()-t)
    ... 
    0.10
    0.04
    0.01
    0.01
    0.01
    0.01
    0.02
    0.01
    0.01
    0.13

(It's an active server, so variability in response time is to be expected.)
It's multi-threaded, spinning off a thread for each request.  Even over the
internet I can get round-trip echo times in the neighborhood of 0.2 seconds.

Skip