I just merged async (Twisted) support into the Python ping.fm library today and have just taken it for a test drive. I do love Twisted :-) The Twisted pyngfm API usage is identical to the synchronous API, with the usual exception of using deferreds and callbacks.
Here's some example usage, the client I now use for command-line updates to Twitter, Identi.ca, Tumblr, Facebook, LinkedIn, Jaiku, and even Flickr (note that the keys are stored in an .ini-style config file):
There's another example in the README that iterates through the recents posts made to ping.fm. If you do manage to use it and come across any issues, be sure to file a ticket.