Step 2: Setting Up Your Computer
To interface between the arduino and twitter, we are going to use python. There is a library that is already put together that enables us to use the twitter API. It's called python-twitter.
After you have installed python, install the python-twitter library and all its dependencies. If you run into trouble just consult the documentation over on the python-twitter website.
Next, install the Arduino IDE so you can program your arduino and talk to it via serial port.
Once those are set up and working, time to go grab your credentials from twitter.com