I've removed my credentials from the init function in the Streaming class. Credentials can be obtained at: https://dev.twitter.com/
The application defaults to "tacos" if sys.argv is not provided.
Tested on OS X 10.6 Python 2.6 and OS X 10.8 Python 2.7:
First you'll need the FTDI drivers if you want to use the pyMCU: http://www.ftdichip.com/Drivers/VCP.htm
Then (from here: http://www.pymcu.com/Installation.html#OsxInstall ):
$>sudo easy_install pyserial
$>sudo easy_install pymcu
$>python blinkfor.py tacos
Any microcontroller can be used. Just modify the function "on_status."
I added a new file arduino/pyserial.ino
Tested with python 2.7 on OS X 10.8
It doesn't do much, just sits in a loop waiting for serial commands. If you add this to your arduino (I used an Uno), you should be good to go. Modify the Arduino sketch for more flexibility or a generalized platform for prototyping with Python and Arduino via a serial cable.